Ministry of Health - British Columbia Nutrition Survey: Report on Supplements · 2019-04-24 ·...

British Columbia Nutrition Survey: Report on Supplements

British Columbia Nutrition Survey:

Report on Supplements

Prepared by: Susan I. Barr, Ph.D.

Professor of Nutrition University of British Columbia

Prepared for: Prevention & Wellness Planning, B.C. Ministry of Health Services

February 2004


TABLE OF CONTENTS

List of Tables ..............................................................................................................................ii List of Figures ............................................................................................................................iii Executive Summary ................................................................................................................... iv Acknowledgements...................................................................................................................vii 1.0 INTRODUCTION.........................................................................................................1 2.0 METHODS .................................................................................................................... 3

2.1 Non-response Questionnaire............................................................................... 3 2.2 Supplement Intake .............................................................................................. 3

3.0 RESULTS and DISCUSSION ..................................................................................... 6

3.1 Response Rate..................................................................................................... 6 3.2 Comparison of Respondents and Non-respondents ............................................ 6 3.3 Prevalence of Use of Vitamin-Mineral and Other Supplements by

BC Adults............................................................................................................ 7 3.4 Number of Vitamin and/or Mineral Supplements Used ................................... 11 3.5 Use of Supplements Containing Specific Nutrients on the Day

Before the Survey ............................................................................................. 13 3.6 Use of Supplements Containing Specific Nutrients during the Month

Before the Survey ............................................................................................. 17 3.7 Nutrient Intakes from Supplements .................................................................. 20 3.8 Effect of Supplement Intake on the Prevalence of Nutrient Inadequacy.......... 29 3.9 Effect of Supplement Use on the Prevalence of Excessive Intakes.................. 35 3.10 Other Supplements Used................................................................................... 38

4.0 CONCLUSIONS ......................................................................................................... 41 5.0 REFERENCES............................................................................................................ 43

i


LIST OF TABLES Table 2.1 Observed and weighted sample sizes for the BC Nutrition Survey.................... 5

Table 3.1 Percent of BC adult population taking any supplement (vitamin-mineral and/or other).........................................................................................................7

Table 3.2 Percent of BC adult population taking vitamin and/or mineral supplements only, other supplements only, and both vitamin and/or mineral and other supplements ............................................................................9

Table 3.3 Number of vitamin and/or mineral supplements taken yesterday by BC adults taking one or more nutritional supplements.......................................................12

Table 3.4 Number of vitamin and/or mineral supplements taken yesterday by BC adults, by age and sex ........................................................................................13

Table 3.5 Percentage (and 95% confidence interval) of BC adults taking supplements containing various nutrients yesterday by age and sex......................................16

Table 3.6 Percentage (and 95% confidence interval) of BC adults taking supplements containing various nutrients last month by age and sex ....................................19

Table 3.7. Minimum, median and maximum nutrient intakes from supplements yesterday and during the last month by age and sex..........................................22

Table 3.8 Effect of supplement use on the apparent prevalence (and 95% confidence interval) of nutrient inadequacy in BC adults ....................................................30

Table 3.9 Effect of supplement use on median usual calcium intakes of BC adults ..................................................................................................................33

Table 3.10 Effect of supplement use on proportion of BC adults meeting the adequate intake (AI) for calcium .......................................................................34

Table 3.11 Effect of supplement use on median usual pantothenic acid intakes of BC adults............................................................................................................35

Table 3.12 Effect of supplement use on the proportion of BC adults meeting the adequate intake (AI) for pantothenic acid..........................................................35

Table 3.13 Effect of supplement use on the prevalence of BC adults with usual intakes above the tolerable upper intake level (UL) ..........................................37

Table 3.14 Percent of BC adult population using non-vitamin-mineral supplements .........39

Table 3.15 Other supplements used by participants in the BC Nutrition Survey ................40

ii


LIST OF FIGURES Figure 3.1. Percent of British Columbians consuming a vitamin and/or mineral

supplement by sex and age ................................................................................. 11 Figure 3.2. Prevalence of inadequate vitamin and mineral intakes from food alone,

and food from plus supplements, among British Columbia adults..................... 32
iii


Executive Summary

The British Columbia Nutrition Survey (BCNS) was conducted in 1999 by Health

Canada and the BC Ministry of Health Planning, in association with the University of British

Columbia, to obtain comprehensive up-to-date information on the eating habits and body weights

of adult British Columbians. The province-wide survey included 1823 participants aged 19 to 84

years, and involved 90-minute, in-home interviews by trained public health nurses and

nutritionists. Several questionnaires were used to assess food consumption and priority nutrition

issues, including a 24-hour recall, a food frequency questionnaire, and a general nutrition

questionnaire focusing on physical activity, healthy weight and body image, and food security.

Socio-demographic information and measured height, weight and waist circumference were also

collected from the participants.

Although the BCNS had several objectives, the data presented herein relate to only one;

namely, to assess the extent of supplement use and its impact on nutrient adequacy. The key

findings reported in this document are highlighted below.

• Supplement use is common among BC adults, with 46% of the population having taken one

or more supplements on the previous day, and 64% having done so within the previous

month. Although the majority of supplement users used only one or two supplements, almost

one in four supplement users had taken four or more supplements the previous day.

• Supplement use tended to be more common among women than men, and in adults over the

age of 50 compared to younger adults.

• Use of vitamin and/or mineral supplements was more common than use of other types of

supplements: Fifty-seven percent of the population had used one or more vitamin and/or

mineral supplements during the past month, while 33% had used one or more other

iv


supplements.

• Supplements containing vitamin C, vitamin E and calcium were the most commonly used

vitamin and/or mineral supplements. A wide variety of non-vitamin/mineral supplements was

used: Glucosamine and/or chondroitin sulphate, garlic, various oils, echniacea and gingko

biloba were reported most frequently.

• Although a synthetic source of vitamin B12 is recommended for adults over the age of 50,

over half the population of older adults had not consumed any supplemental vitamin B12

during the month before the survey.

• The recommended intakes for vitamin D are 400 mcg/d and 600 mcg/d for adults aged 51-70

and 71 and above, respectively. Although data on vitamin D intakes from food were not

available in the BCNS, these recommended intakes are very difficult to obtain from diet

alone. However, most older adults had not taken a supplement providing vitamin D in the

month before the survey.

• Consideration of supplement use significantly reduced the population prevalence of nutrient

inadequacy (as approximated by the percentage below the Estimated Average Requirement)

for folate, vitamin B12 and vitamin C, and differences were of borderline significance for

vitamin B6 and magnesium.

• Although supplement use increased median calcium intakes and the percentage of individuals

meeting the Adequate Intake (AI), median intakes remained below the AI for all age/sex

groups except young men, whose median intake exceeded the AI whether or not supplement

use was considered.

• Supplement use was associated with small increases (<1% - 7%) in the proportion of the

population with intakes above the Tolerable Upper Intake Level (UL) for calcium, vitamin

v


B6, folic acid, vitamin C, vitamin E, iron and zinc. For niacin, 10-37% of various age/sex

groups had intakes exceeding the UL.

Potential implications of these findings for health professionals and health planners

include the need to consider supplement use when assessing dietary intake; the likelihood that

future dietary guidance may need to include recommendations for supplement use; the need to

develop effective methods for educating the public about supplements; the need to monitor the

potential for adverse consequences arising from excessive supplement intake; and the need for

health professionals to inquire about their clients’ use of all types of supplements.

vi


Acknowledgements

In addition to myself, other members of the Investigative Team for the BCNS included

Lisa Forster-Coull (principle investigator) and Ryna Levy-Milne (co-investigator). I thank both

Lisa and Ryna for helpful comments and suggestions on earlier versions of this document. The

entire Investigative Team thanks Health Canada and the BC Ministry of Health Planning for

jointly funding the study, and the British Columbians who generously gave their time to

participate in the study. Many individuals contributed to the success of the BCNS, and are

acknowledged by name in the BC Nutrition Survey Nutrient Report (1).

vii


1.0 INTRODUCTION The British Columbia Nutrition Survey (BCNS) was conducted by Health Canada and the

BC Ministry of Health Planning, in association with the University of British Columbia, to

obtain comprehensive up-to-date information on the eating habits and body weights of adult

British Columbians. Similar provincial nutrition surveys have been conducted in all other

provinces beginning in 1988 with the Nova Scotia Nutrition Survey. This report is one of a

series arising from the BCNS, and as such, it relates to only one of the six objectives the survey

was designed to meet; namely “to determine the contribution of major food groups, food types

and dietary supplements to the diet”. Readers are referred to the BCNS Nutrient Report for a full

description of the rationale for the study, a literature review pertaining to the study’s objectives,

complete descriptions of study methodology, and data on response rates (1). The province-wide

survey involved 90-minute, in-home interviews conducted by trained public health nurses and

nutritionists utilizing several questionnaires to assess food consumption and priority nutrition

concerns. The questionnaires included a 24-hour recall that also ascertained supplement use, a

food frequency questionnaire, and a general nutrition questionnaire focusing on physical activity,

healthy weight and body image, and food security. Socio-demographic information, height,

weight and waist circumference measurements were also collected from the approximately 1800

participants, aged 19 to 84 years. The data reported herein were obtained from the 24-hr recall.

Assessment of the contribution of dietary supplements to the diets of British Columbians

is relevant, as increasing proportions of North Americans are using both nutritive and non-

nutritive supplements. For example, in the third National Health and Nutrition Examination

Survey (NHANES-III) study, 34.9% of men and 43.8% of women in the United States reported

using at least one supplement during the past month (2). Another national US sample found that

1


40% of adults had used one of more vitamin/mineral supplements during the past seven days (3),

while 14% reported using one or more herbal preparations. Fewer Canadian studies are

available, but the Food Habits of Canadians Study found that 41% of participants aged 18 to 65

used at least one supplement on the day prior to the survey: Thirty-eight percent used one or

more nutritive supplements, and 15% used one or more herbal preparations (4).

In the recently-released Dietary Reference Intakes (DRIs) (5-9), supplement use is

acknowledged to contribute to meeting nutrient requirements. When diets of populations are

assessed to determine the adequacy of nutrient intakes, assessment should be based on total

intake, including supplements (10). Furthermore, use of a supplement or fortified food is

explicitly or implicitly recommended for some age/sex groups: This includes folic acid for

women of child-bearing potential, and vitamins B12 and D for adults over 50. However,

supplement use also has the potential to lead to adverse effects from excessive nutrient intakes.

For some nutrients, such as niacin, magnesium, folic acid and vitamin E, the Tolerable Upper

Intake Level (UL) applies only to intakes from fortified foods and/or supplements. For these

reasons, current information on supplement use should be available to contribute to the

identification of priority areas for nutrition programming.

2


2.0 METHODS 2.1 Non-response Questionnaire

As discussed more completely in the British Columbia Nutrition Survey Report on

Energy and Nutrient Intakes (1), a low response rate suggests the potential for bias, as non-

responders may differ systematically from respondents. Accordingly, survey results may not be

generalizable to the general adult population in British Columbia. In an effort to assess the

direction and/or extent of potential bias associated with a low response rate, the non-responders

were asked to complete a short survey including questions on smoking, consumption of bread,

milk and supplements, and marital status. The question on supplement use asked “During the

past month, did you take any vitamin-mineral supplement?”.

2.2 Supplement Intake

Supplement data were obtained during the 24-hr recall portion of the in-home interview.

Participants were first asked whether they took any nutritional supplements, vitamins, minerals,

or herbal, botanical or homeopathic preparations yesterday, which was also the day used for the

24-hr recall of food intake. This was followed by a question about whether they took any other

supplements (i.e., that differed from the ones taken yesterday) within the past month. Next, for

each supplement, participants were asked to provide its specific name and DIN (drug

identification number). Because interviews were conducted in participants’ homes, in most cases

this information was recorded directly from the supplement label. Finally, participants indicated

how often they took the supplement (per day, per week or per month) as well as the number of

pills (or tablets, capsules, teaspoons) usually taken on each occasion.

3


Supplement data were entered into the Health Canada supplement database, using the

DIN when possible. For the purposes of analysis, vitamin and/or mineral supplements were

defined as supplements containing recognized vitamins and minerals, while other supplements

included supplements not containing recognized vitamins and minerals, but considered by the

respondent to be a supplement. Examples of non-nutritional supplements included herbs and

natural products (e.g., garlic, gingko, echinacea, homeopathic products, glucosamine). In some

cases this latter category also included substances containing known nutrients (e.g., oils that

contain vitamin A or D, but were not marketed as a vitamin A or D supplement).

For each individual who used nutritional supplements, nutrient intake from supplements

was expressed both as the intake “yesterday” and as the intake during the past month. Monthly

supplement intake data were expressed as daily amounts, and were combined with the adjusted

usual nutrient intake from food to yield the distribution of usual nutrient intake from food plus

supplements.

In most cases, data on the prevalence of supplement use are presented as the point

estimates for the sample, and the 95% confidence intervals (95% CI, the range within which the

population means could lie) are also presented. Whether subgroup means differ significantly can

be estimated by determining whether or not the 95% CIs overlap. For example, if the estimated

prevalence of use by men aged 19-30 was 24% (95% CI 12% - 31%), and was compared to an

estimated prevalence of 40% (95% CI 33% - 48%) for men aged 51-70, it could be concluded the

older men were more likely to use supplements than men aged 19-30, because the two sets of

confidence intervals do not overlap.

All data presented in this report have been weighted. Observed and weighted sample

sizes according to the Dietary Reference Intake age-sex groups are shown in Table 2.1.

4


Table 2.1 Observed and weighted sample sizes for the BC Nutrition Survey

Men (age in years) Women (age in years) Sample size

19-30 31-50 51-70 >71 19-30 31-50 51-70 >71

Observed 142 205 249 271 176 266 282 230

Weighted 235 366 217 84 229 371 221 99

From: BBCA Technical Document E451313-011B V1.

5


3.0 RESULTS AND DISCUSSION

3.1 Response Rate

In a large population survey such as the BCNS, the response rate depends on whether

unresolved cases (those individuals that couldn’t be contacted) were eligible to participate in the

survey. Lower and upper bounds for the response rate can be calculated based on the assumption

that all unresolved cases are eligible (lower bound), or that all unresolved cases are ineligible

(upper bound). The true rate lies somewhere between these two values. (Further details on the

response rate and its calculation are provided in the BCNS Report on Energy and Nutrient

Intakes [1]). In the BCNS, the lower and upper bounds of the response rate were 42% and 52%.

Thus, potential for non-response bias existed.

3.2 Comparison of Respondents and Non-respondents

About 66% of non-respondents completed the non-response survey, and their responses

were compared to those of study participants. Of relevance to this report was the finding that

respondents were significantly more likely than non-respondents to report use of a vitamin-

mineral supplement during the past month: For all adults, 66.2% of respondents had used a

supplement compared to 59.8% of non-respondents. Among men, 60.2% and 53.1% of

respondents and non-respondents, respectively, had used a supplement, and for women,

corresponding proportions were 71.7% and 66.4%. Accordingly, the true prevalence of

supplement use among BC adults is likely somewhat lower than the prevalence estimated in the

BCNS, and this should be kept in mind when interpreting the survey findings.

6


3.3 Prevalence of Use of Vitamin-Mineral and Other Supplements by BC Adults

Table 3.1 shows the proportions of BC men and women, by age group, who had taken

any type of supplement yesterday and during the past month. Overall, almost half of the

population took a supplement yesterday, and closed to two-thirds had taken a supplement within

the past month. Women appeared to be more likely than men to use supplements, both yesterday

and within the past month, and in some age groups the differences were significant (as assessed

by non-overlapping 95% Confidence Intervals). The proportions of adults using supplements

increased with age, particularly in adults over the age of 50. The BC Nutrition Survey findings

are generally comparable to those of the Food Habits of Canadians study, which found that 41%

of adults had used one or more supplements on the day before the survey (4). In that study,

women were also more likely than men to use supplements, and the prevalence of use increased

with age, from 28% of men and 35% of women aged 18 to 35, to 42% of men and 57% of

women aged 50 to 65. The Food Habits of Canadians study did not include individuals over the

age of 65, who were most likely to use supplements in the BCNS.

Table 3.1 Percent of BC adult population taking any supplement (Vitamin-mineral and/or other)

Supplement taken yesterday

Supplement taken in past month

Sex/Age Group

Percent (95% CI) Percent (95% CI) Men 19-30 28 (19 – 37) 54 (44 – 64) 31-50 35 (27 – 43) 52 (44 – 59) 51-70 44 (36 – 53) 59 (51 – 68) 71+ 65 (56 – 75) 70 (61 – 79) Women 19-30 38 (29 – 48) 62 (53 – 72) 31 – 50 46 (39 – 53) 69 (62 – 76) 51 – 70 72 (64 – 80) 79 (72 – 86) 71+ 80 (73 – 88) 84 (77 – 91) All Men and Women 46 64 Data from: BBCA Technical Document E451313-011C V3

7


Table 3.2 shows the proportions of BC adult men and women who took vitamin and/or

mineral supplements only, “other” supplements only, or both vitamin and/or mineral and “other”

supplements. As described earlier, the “other” supplement category includes some supplements

that contain nutrients (such as essential fatty acids and fat-soluble vitamins in oils), but consists

mainly of substances that are not recognized nutrients, although are believed by some to have

health benefits. Overall, it can be seen that more British Columbians used only vitamin and/or

mineral supplements as compared to only “other” supplements (e.g., for all adults, 24% used

only a vitamin and/or mineral supplement yesterday while 4% used only an “other” supplement

yesterday). Most of those who use “other” supplements also use a vitamin and/or mineral

supplement, as revealed by the fact that 18% of adults took both a vitamin and/or mineral

supplement and an “other” supplement yesterday. Similar observations were apparent for use of

supplements during the past month. Data from the Food Habits of Canadians Study were

consistent with the BC results. In that study, 26% took only a nutritional supplement yesterday,

11% took both nutritional and herbal supplements, and 4% used only herbal supplements (4).

8


Table 3.2 Percent of BC adult population taking vitamin and/or mineral supplements only, other supplements only, and both vitamin and/or mineral and other supplements

Supplement taken yesterday

Supplement taken in past month

Sex/Age Group

Percent (95% CI) Percent (95% CI) Vitamin and/or Mineral Supplements Only

Men 19 – 30 yr 17 (9 – 25) 33 (23 – 42) 31 – 50 yr 19 (13 – 26) 27 (19 – 35) 51 – 70 yr 22 (16 – 28) 28 (20 – 35) >71 yr 30 (22 – 38) 29 (22 – 37)

Women 19 – 30 yr 24 (15 – 32) 34 (24 – 43) 31 – 50 yr 26 (19 – 33) 31 (24 – 39) 51 – 70 yr 27 (21 – 34) 29 (22 – 36) >71 yr 39 (29 – 49) 40 (30 – 50)

All Men and Women 24 (21 – 26) 31 (28 – 34) Other Supplements Only

Men 19 – 30 yr 4 (0.5 – 8) 9 (3 – 14) 31 – 50 yr 6 ( 2 – 10) 9 (5 – 13) 51 – 70 yr 6 (2 – 11) 9 (3 – 14) >71 yr 3 (0.6 – 5) 4 (1 – 6)

Women 19 – 30 yr 2 (0.4 – 3) 4 (0.8 – 8) 31 – 50 yr 3 (0.4 – 5) 6 (2 – 9) 51 – 70 yr 7 (2 – 11) 4 (2 – 7) >71 yr 5 (0.7 – 9) 4 (0 – 9)

All Men and Women 4 (3 – 6) 7 (5 – 8)

Both Vitamin and/or Mineral and Other Supplements

Men 19 – 30 yr 7 (2 – 12) 13 (6 – 19) 31 – 50 yr 10 (5 – 15) 16 (10 – 22) 51 – 70 yr 16 (10 – 22) 23 (16 – 30) >71 yr 33 (24 – 41) 37 (29 – 46)

Women 19 – 30 yr 13 (6 – 20) 24 (16 – 32) 31 – 50 yr 17 (12 – 22) 32 (25 – 40) 51 – 70 yr 38 (30 – 46) 45 (37 – 53) >71 yr 37 (27 – 47) 40 (30 – 50)

All Men and Women 18 (16 – 20) 26 (24 – 29) Data from: BBCA Technical Document E451313-011C V3

9


The total proportions of British Columbians using vitamin and/or mineral supplements

yesterday and during the past month are shown in Figure 3.1. Data shown in this figure were

obtained by adding together the proportions who used only a vitamin and/or mineral supplement

and who used both a vitamin and/or mineral supplement and an other supplement, as shown in

Table 3.2. It can be seen that within each age group, women appeared to be more likely to use

nutritional supplements than men, and that in general, the proportions using a supplement either

yesterday or within the past month increased with age. Also, in the oldest age group it appeared

that the proportions who used a supplement yesterday and who used a supplement within the past

month were quite similar, suggesting that most older adults who use nutritional supplements do

so on a daily basis. In contrast, in the youngest age group, for both men and women, the

proportion that had used a supplement within the past month was greater than the proportion that

had used a supplement yesterday. This suggests that among younger adults, occasional use of

supplements may be more common.

10


Figure 3.1. Percent of British Columbians consuming a vitamin and/or mineral supplement by sex and age

0102030405060708090

19-30

31-50

51-70

71+ 19-30

31-50

51-70

71+

Perc

ent

YesterdayPast month

Men, age group Women, age group

3.4 Number of Vitamin and/or Mineral Supplements Used

Table 3.3 shows the number of vitamin and/or mineral supplements used by BC adults

who used one or more supplements on the day prior to the survey. The largest proportions of

both men and women used only one supplement; however, for all age-sex groups except men

aged 19-30, more than 50% used two or more supplements. Finally, over 25% had taken four or

more vitamin and/or mineral supplements, and almost 9% had taken six or more. The prevalence

of multiple supplement use among BC adults appears similar to that reported for Canadians as a

whole. In the Food Habits of Canadians study, 57% of supplement users used more than one

supplement on the day prior to the survey (4), compared to 65% of British Columbian

supplement users.

11


Table 3.3 Number of vitamin and/or mineral supplements taken yesterday by BC adults taking one or more nutritional supplements

Number of vitamin and/or mineral supplements taken yesterday by those who took a supplement yesterday

Sex/age group Consumed supplement yesterday

(%) 1 (%) 2 (%) 3 (%) 4 (%) 5 (%) >6 (%)

Men 19 – 30 yr 24 67.9 14.3 3.6 10.7 3.6 - 31 – 50 yr 29 42.6 24.6 13.1 14.8 1.6 3.3 51 – 70 yr 38 41.9 26.5 13.7 8.6 2.6 6.8 >71 yr 63 34.7 24.4 14.8 12.5 7.8 5.7

Women 19 – 30 yr 37 48.4 26.6 14.1 6.2 - 4.7 31 – 50 yr 43 35.6 21.2 18.6 5.1 5.9 13.6 51 – 70 yr 65 23.4 24.0 22.8 12.2 7.2 12.6 >71 yr 76 34.8 23.4 16.5 10.8 5.9 8.7

All men and women 42 34.8 23.4 16.5 10.8 5.9 8.7 Data from: BBCA Technical Document E451313-011C V3

Table 3.4 also presents data on the numbers of vitamin and/or mineral supplements used,

but it includes those who did not use any supplements. For men and women combined, over half

did not use a supplement yesterday, but more than 10% of the BC population had used four or

more vitamin and/or mineral supplements. Use of multiple supplements increased with age: for

example, about 3-4% of those aged 19-30 used four or more supplements yesterday, compared to

16-19% of those aged 71 and above.

12


Table 3.4 Number of vitamin and/or mineral supplements taken yesterday by BC adults, by age and sex

Number of supplements taken yesterday Sex/age group 0 (%) 1 (%) 2 (%) 3 (%) 4 (%) 5 (%) >6 (%)

Men 19 – 30 yr 76 16.3 3.4 0.8 2.6 0.9 - 31 – 50 yr 71 12.4 7.1 3.8 4.3 0.5 1.0 51 – 70 yr 62 15.9 10.1 5.2 3.3 1.0 2.6 >71 yr 37 21.9 15.4 9.3 7.9 4.9 3.6

Women 19 – 30 yr 63 17.9 9.8 5.2 2.3 - 1.7 31 – 50 yr 57 15.3 9.1 8.0 2.2 2.5 5.8 51 – 70 yr 35 15.2 15.6 14.8 7.9 4.7 8.2 >71 yr 24 26.4 17.8 12.5 8.2 4.5 6.6

All men and women

58 14.6 9.8 6.9 4.5 2.5 3.7

Data from: BBCA Technical Document E451313-011C V3

3.5 Use of Supplements Containing Specific Nutrients on the Day Before the Survey

The proportion of BC adults who took supplements containing specific nutrients on the

day before their participation in the survey is shown in Table 3.5 by age group and sex. Overall,

the percent of the adult population taking a nutrient supplement ranged from 14% for phosphorus

to 31% for vitamin C. Vitamin C, calcium and vitamin E were each consumed by about 30% of

BC adults. These three nutrients were also the most commonly consumed in the Food Habits of

Canadians study (4) and in the Slone Survey of Americans (3).

The pattern of supplement use varied considerably by sex and age. Overall, women were

more likely than men to use supplements containing most nutrients. As assessed by non-

overlapping 95% confidence intervals, this sex difference was significant for women aged 31 and

above for calcium and vitamin D; for women 51 and above for riboflavin, thiamin, vitamin A

and vitamin B6; for women aged 51 –70 for folate, niacin, pantothenate, vitamin B12, vitamin C

13


and vitamin E; and for women aged 71 and above for potassium. Other studies did not report use

of specific nutrients by age and sex, so comparisons to other North American data cannot be

made.

Supplement use tended to increase with age. For men, those aged 71 and above were

significantly more likely to calcium and vitamin D supplements than all other age groups. They

were also more likely to use a vitamin C supplement than men aged 19-30, and a vitamin E

supplement than men aged 19-50. Among women, even more differences were apparent.

Compared to women aged 19-50, women aged 71 and above were significantly more likely to

use supplements containing calcium, magnesium, niacin, phosphorus, potassium, riboflavin,

thiamin, vitamin A, vitamin B6, vitamin B12, vitamin C, vitamin D, vitamin E and zinc. With the

exception of vitamin D, which was used by more women aged 71 and above than by women

aged 51-70, the prevalence of use by women aged 51-70 was intermediate and did not differ

from women aged 19-50 or women aged 71 and above. Finally, women aged 51-70 were more

likely than younger women to use a supplement containing calcium or vitamin E.

Use of a supplement containing vitamin B12 by adults over the age of 50 warrants

additional comment, as a synthetic source of this vitamin is recommended for this age group (6).

The reason for this recommendation is that gastric acid levels in 10-30% of older adults are too

low to cleave vitamin B12 from the protein to which it is bound in foods. If this does not occur,

vitamin B12 absorption is reduced. In contrast, synthetic vitamin B12 is present in the free form,

and its absorption is not affected by low gastric acid levels. Because few foods in the Canadian

food supply are fortified with vitamin B12, in most cases a supplement would be required to

obtain the synthetic form of the vitamin. For men and women aged 51-70, the proportions

consuming a supplement containing vitamin B12 on the day prior to the survey were 17% and

14


39% respectively, while for those aged 71 and above, corresponding values were 30% and 47%.

Some of these older adults who do not consume a supplement may be at risk for poor absorption

of vitamin B12, even if their dietary intake is adequate.

Use of vitamin D supplements by older adults also deserves consideration. Unlike

vitamin B12, a supplemental source is not specified. However, because the distribution of

vitamin D in the food supply is limited, it is probable that many older adults would fail to meet

the Adequate Intake (AI) through diet alone (unfortunately, dietary intakes of vitamin D could

not be assessed because the Canadian Nutrient File does not contain data on vitamin D). For

example, for those over age 70, meeting the AI of 15 mcg/d would require the consumption of

six glasses of milk on a daily basis. Thus, for practical purposes, many older adults would need

to consume a supplement to meet the AI, particularly during the winter months when

endogenous synthesis is limited (11). Yet only 17% and 35% of men aged 51-70 and 71 and

above took a supplement containing vitamin D on the day before the survey. Although women

were more likely than men to use a vitamin D supplement (41% and 60% of women aged 51-70

and >71, respectively, took a supplement), the proportions who did not take a supplement were

still substantial. Accordingly, some older adults who did not use a supplement may be at risk for

suboptimal vitamin D status.

15


Table 3.5 Percentage (and 95% confidence interval) of BC adults taking supplements containing various nutrients yesterday by age and sex

Men (%) Women (%) Nutrient 19-30 yr 31-50 yr 51-70 yr >71 yr 19-30 yr 31-50 yr 51-70 yr >71 yr

All

Calcium (mg) 16 (8,24) 17 (11,22) 18 (12,24) 37 (28,46)# 21 (14,29) 34 (27,41) 52 (44,61)* 63 (52,72)* 29 (26,31)

Folic acid (mcg) 14 (7,22) 19 (13,25) 17 (11,22) 27 (19,35) 25 (16,33) 26 (20,33) 38 (30,45) 43 (33,53) 24 (21,27)

Iron (mg) 12 (5,19) 12 (7,17) 12 (7,17) 22 (15,29) 19 (11,26) 22 (16,27) 23 (17,29) 36 (26,46) 18 (16,20)

Magnesium (mg) 15 (8,24) 14 (9,19) 16 (10,21) 25 (18,33) 19 (12,27) 24 (18,30) 38 (30,46)* 42 (32,53)* 22 (20,25)

Niacin (mg NE) 14 (7,22) 19 (13,25) 18 (12,24) 30 (21,39) 25 (16,34) 29 (23,35) 40 (32,48) 50 (39,60) 26 (23,28)

Pantothenate (mg) 14 (7,22) 19 (13,24) 16 (10,22) 21 (14,28) 23 (14,31) 27 (21,33) 36 (28,44) 37 (27,47) 23 (20,26)

Phosphorus (mg) 11 (4,19) 9 (4,14) 11 (6,16) 18 (11,25) 9 (4,15) 13 (8,18) 20 (14,26) 32 (22,43)* 14 (11,16)

Potassium (mg) 10 (4,17) 10 (6,14) 11 (6,15) 20 (13,27) 13 (6,20) 16 (11,22) 21 (15,28) 34 (24,44)* 15 (13,17)

Riboflavin (mg) 15 (7,23) 19 (13,25) 17 (12,23) 26 (18,34) 25 (16,34) 29 (23,35) 39 (31,47) 50 (40,61)* 26 (23,28)

Thiamin (mg) 14 (7,22) 19 (13,25) 17 (11,23) 26 (18,34) 25 (16,34) 29 (23,35) 39 (31,47) 50 (40,61)* 25 (23,28)

Vitamin A (RE) 16 (3,25) 16 (10,21) 16 (11,22) 30 (21,38) 23 (15,31) 24 (18,30) 33 (26,41) 51 (41,61)* 23 (21,26)

Vitamin B6 (mg) 14 (7,22) 19 (14,25) 18 (12,24) 27 (19,35) 25 (16,34) 29 (23,36) 39 (32,47) 51 (40,61)* 26 (23,29)

Vitamin B12 (mcg) 14 (7,22) 19 (13,25) 17 (11,22) 30 (21,38) 24 (15,33) 28 (21,34) 39 (31,47) 47 (36,57)* 25 (22,28)

Vitamin C (mg) 20 (12,28) 24 (18,31) 24 (18,31) 39 (30,49)* 29 (21,38) 33 (26,39) 46 (38,54) 58 (48,68)* 31 (28,34)

Vitamin D (IU) 14 (7,22) 15 (10,21) 17 (12,23) 35 (26,43)# 21 (13,29) 28 (22,34) 41 (32,49) 60 (50,69)# 25 (23,28)

Vitamin E (eq) 18 (10,26) 18 (12,23) 29 (22,36) 45 (36,55)* 25 (17,34) 27 (21,33) 50 (42,58)* 63 (54,73)* 30 (27,32)

Zinc (mg) 13 (5,20) 13 (8,17) 14 (9,20) 23 (16,30) 18 (10,25) 20 (14,26) 29 (21,36) 41 (32,53)* 19 (17,21)

* Compared to at least one younger same-sex age group, a higher proportion of this age group took a supplement yesterday. # Compared to all younger same-sex age groups, a higher proportion of this age group took a supplement yesterday.

16


3.6 Use of Supplements Containing Specific Nutrients during the Month Before the Survey

The proportions of BC adults who took supplements containing specific nutrients on one

or more days in the month before their participation in the survey are shown in Table 3.6 by age

group and sex. Overall, the percent of the adult population taking a nutrient supplement ranged

from 19% for phosphorus to 46% for vitamin C. Similar to the findings for supplements taken

on the day before the survey, vitamin C, calcium and vitamin E were used by the largest

proportions of BC adults, in this case by more than 40%.

As was the case for use of supplements containing nutrients on the day prior to the

survey, women were more likely than men to use supplements of most nutrients during the

month before the survey. As assessed by non-overlapping 95% confidence intervals, this was

significant for those aged 31 – 50 for iron and pantothenate; for those aged 31 – 70 for vitamin E,

vitamin C and niacin; for those aged 31 and above for calcium, vitamin D, vitamin B6 and

riboflavin; for those aged 51 – 70 for folate, vitamin B12, and magnesium; for those aged 51 and

above for thiamin; and for those aged 71 and above for vitamin A.

Age differences were also apparent, but these were less common than was seen for use of

nutrient supplements on the day before the survey. For men, the only significant age difference

was for vitamin E, with men aged 71 and above more likely to use a supplement than men aged

31 – 50. For women, those aged 71 and above were more likely than those aged 19-30 to have

used supplements containing phosphorus, vitamin A and zinc. They were also more likely than

women aged 19-50 to have used a calcium supplement, and were more likely than all younger

women to have used a supplement with vitamin D. Women aged 51 –70 were more likely than

those aged 19 –30 to have used a calcium supplement, and women aged 51 and above were more

likely than those aged 19-30 to have used a supplement with vitamin E.

17


As mentioned with regard to supplement intake on the day before the survey, additional

comments about the use of supplements containing vitamin B12 by adults over 50 are warranted.

For men and women aged 51 to 70, 24% and 44% respectively had taken a supplement on one or

more days of the month preceding the survey, while for those aged 71 and above, corresponding

values were 33% and 49%. In other words, more than half the population of older adults had not

consumed any synthetic vitamin B12 in the month before the survey, suggesting that this may be

a nutrient of concern for this age group.

Similarly, Vitamin D may also be a nutrient of concern. Only 25% of men and 44% of

women aged 51-70 had taken a supplement containing vitamin D in the past month. For those

aged 71 and above, corresponding proportions were 37% and 66%. Without data on serum 25-

OH-Vitamin D levels, it is not possible to assess vitamin D status. However, recent reports

suggest that a majority of older Canadians who do not use supplements are at risk for suboptimal

vitamin D status (12).

18


Table 3.6 Percentage (and 95% confidence interval) of BC adults taking supplements containing various nutrients last month by age and sex

Men (%) Women (%)

Nutrient 19-30 yr 31-50 yr 51-70 yr >71 yr 19-30 yr 31-50 yr 51-70 yr >71 yr

All

Calcium (mg) 27 (18,36) 25 (18,32) 26 (19,34) 39 (30,48) 37 (28,46) 50 (42,58) 62 (54,70)* 69 (60,77)* 40 (36,43)

Folic acid (mcg) 29 (20,38) 29 (22,35) 24 (17,31) 30 (22,38) 42 (33,51) 42 (34,49) 42 (34,50) 45 (35,55) 35 (32,38)

Iron (mg) 23 (14,31) 21 (15,28) 19 (12,26) 24 (17,31) 28 (19,36) 36 (29,43) 24 (18,31) 40 (30,50) 27 (24,29)

Magnesium (mg) 26 (17,36) 22 (15,29) 23 (15,30) 28 (20,36) 28 (19,36) 40 (21,47) 42 (34,50) 46 (36,56) 31 (28,34)

Niacin (mg NE) 31 (21,40) 30 (23,37) 25 (18,32) 33 (24,42) 43 (34,52) 45 (38,52) 46 (38,54) 52 (42,62) 37 (34,40)

Pantothenate (mg) 27 (18,36) 27 (20,33) 23 (16,31) 23 (16,30) 36 (27,46) 41 (34,48) 38 (30,46) 39 (29,49) 32 (29,35)

Phosphorus (mg) 21 (12,29) 15 (9,20) 17 (11,24) 20 (13,27) 16 (9,23) 21 (15,27) 22 (16,29) 34 (25,44)* 19 (17,22)

Potassium (mg) 19 (11,27) 17 (11,23) 17 (11,24) 22 (15,29) 20 (13,28) 29 (22,36) 25 (19,32) 38 (28,48) 23 (20,25)

Riboflavin (mg) 32 (22,41) 30 (24,37) 25 (17,32) 30 (21,38) 43 (23,52) 45 (38,52) 45 (36,53) 52 (42,63) 37 (34,40)

Thiamin (mg) 29 (20,39) 30 (23,37) 24 (17,31) 29 (20,37) 43 (34,52) 45 (37,52) 45 (36,53) 52 (42,63) 37 (34,40)

Vitamin A (RE) 31 (22,41) 27 (20,34) 25 (18,32) 33 (25,42) 34 (25,43) 40 (33,47) 37 (30,45) 55 (45,65)* 34 (31,37)

Vitamin B6 (mg) 31 (22,41) 31 (24,37) 25 (18,33) 31 (22,39) 43 (34,52) 45 (38,52) 45 (37,53) 53 (43,63) 38 (35,41)

Vitamin B12 (mcg) 29 (20,39) 29 (22,36) 24 (17,31) 33 (24,41) 40 (31,50) 43 (36,50) 44 (36,53) 49 (39,59) 36 (33,39)

Vitamin C (mg) 41 (31,51) 38 (31,45) 35 (27,43) 44 (35,54) 50 (41,60) 53 (46,60) 55 (47,63) 60 (51,70) 46 (43,49)

Vitamin D (IU) 28 (19,37) 26 (19,32) 25 (18,33) 37 (28,46) 34 (25,44) 43 (36,50) 44 (36,53) 66 (58,75)# 36 (33,39)

Vitamin E (eq) 30 (21,40) 30 (23,37) 38 (29,46) 50 (40,60)* 37 (28,46) 45 (38,52) 56 (48,64)* 65 (56,75)* 41 (38,44)

Zinc (mg) 25 (16,33) 21 (15,28) 23 (16,30) 26 (19,33) 26 (18,34) 35 (28,42) 34 (26,42) 45 (35,55)* 28 (26,31)

* Compared to at least one younger same-sex age group, a higher proportion of this age group took a supplement in the previous month. # Compared to all younger same-sex age groups, a higher proportion of this age group took a supplement in the previous month.

19


3.7 Nutrient Intake from Supplements

Table 3.7 presents data on the minimum, median and maximum intake of

nutrients from supplements by those using supplements on the day before the survey

(‘yesterday’) and during the month before the survey (‘last month’). To facilitate

comparisons, the table also lists the recommended intake (Recommended Dietary

Allowance [RDA] or Adequate Intake [AI]) as well as the Tolerable Upper Intake Level

[UL]. Several observations may be made from the data presented in the table:

• For many nutrients, the median intake taken ‘yesterday’ corresponds to the

amounts found in typical “1-a-day” multivitamin/mineral supplements. These

amounts are below the recommended intakes for nutrients such as calcium,

phosphorus and magnesium, while they approximate (~1-3 times) the

recommended intakes for Vitamin D, thiamin, riboflavin, niacin, folic acid,

pantothenate, vitamin A, iron and zinc. Median supplemental intakes of

vitamin B12, vitamin B6, vitamin C and vitamin E in several age/sex groups

were well above the RDA.

• When the usual intakes over the past month are examined, similar patterns are

evident, although usual intakes of vitamin C fall to within 1-3 times the RDA

for most age-sex groups. This may reflect the tendency for some people to take

large doses of vitamin C only when they feel unwell, rather than on a daily

basis.

• Because the UL applies to usual intake, it is most informative to examine

intakes over the past month against the UL. When considering nutrient intake

from supplements alone, it can be seen that most maximum intakes of age-sex

20


groups did not exceed the UL for calcium, phosphorus, vitamin D, and vitamin

E. In contrast, maximum intakes of several age-sex groups were above the ULs

for folic acid, iron, magnesium, vitamin B6, vitamin C, and zinc. For niacin, the

median intakes of several age-sex groups and the maximal intakes of all age-sex

groups exceeded the UL. It is not possible to determine whether maximal

vitamin A intakes are above the UL, since the supplemental intakes include

vitamin A contributions from both β-carotene and preformed retinol, while the

UL applies only to preformed retinol. Further information on the role of

supplements in contributing to intakes above the UL is presented in Section 3.9.

21


Table 3.7 Minimum, median and maximum nutrient intakes from supplements yesterday and during the last month by age and sex

Yesterday Last monthNutrient

DRI group RDA1/AI2 UL3

Minimum Median Maximum Minimum Median Maximum

M 19-30 1000 2500 87.5 175 1219 0.3 125 1192

M 31-50 1000 2500 6.2 175 1815 4.1 99 1645

M 51-70 1200 2500 5.1 200 1500 2.9 200 2311

M 71+ 1200 2500 1.6 300 1282 1.6 223 1201

F 19-30 1000 2500 15.5 200 1175 0.2 132 3579

F 31-50 1000 2500 3.1 453 1516 1.5 196 1500

F 51-70 1200 2500 3.1 500 4203 0.3 375 4201

Calcium (mg)

F 71+ 1200 2500 3.1 490 2500 3.1 405 1725

M 19-30 4007 10005 100 600 2400 38 250 2400

M 31-50 4007 10005 10 400 5400 63 263 5400

M 51-70 4007 10005 100 400 2000 67 400 2000

M 71+ 4007 10005 50 407 5000 89 400 5000

F 19-30 4007 10005 7 600 3021 70 329 1200

F 31-50 4007 10005 14 400 2000 110 300 1992

F 51-70 4007 10005 50 400 4000 120 400 2760

Folic acid (mcg)

F 71+ 4007 10005 80 500 3500 94 500 3500

M 19-30 8 45 5.0 10 60 0.1 6.6 60

M 31-50 8 45 2.5 10 33 0.3 3.9 31

M 51-70 8 45 4.0 5.0 40 0.2 4.0 36

Iron (mg)

M 71+ 8 45 3.3 10.0 122 0.4 9.0 122

22


Table 3.7 (Cont’d) Yesterday Last monthNutrient

DRI group RDA/AI UL


F 19-30 18 45 2.6 18.0 81 0.2 8.2 85

F 31-50 18 45 1.4 10.0 221 0.3 7.1 221

F 51-70 8 45 4.0 4.0 59 0.7 4.0 30

Iron (mg)

F 71+ 8 45 4.0 4.0 221 0.3 4.0 101

M 19-30 400 3504 26.7 63 600 0.9 50 600

M 31-50 420 3504 5.6 100 750 0.2 38 750

M 51-70 420 3504 5.6 100 668 1.6 82 488

M 71+ 420 3504 5.6 100 1000 5.1 100 821

F 19-30 310 3504 17.0 100 740 4.5 43 740

F 31-50 320 3504 5.6 100 1500 0.2 66 1500

F 51-70 320 3504 5.6 167 837 1.6 150 837

Magnesium (mg)

F 71+ 320 3504 5.6 100 600 5.6 100 60099

M 19-30 16 355 20.0 40 120 0.1 20.5 120

M 31-50 16 355 1.0 40 100 0.2 24.6 100

M 51-70 16 355 6.0 40 1500 3.9 34.3 1500

M 71+ 16 355 10.0 40 1500 1.6 40.0 1500

F 19-30 14 355 0.7 40 200 1.6 19.5 90

F 31-50 14 355 0.1 50 240 0.5 27.6 240

F 51-70 14 355 0.4 40 4057 0.4 40.0 4952

Niacin (mg NE)

F 71+ 14 355 6.6 40 615 0.6 40.0 424

23



DRI group RDA/AI UL


M 19-30 5 - 5.0 10 60 0.1 8 60

M 31-50 5 - 0.1 20 90 0.1 10 90

M 51-70 5 - 5.0 10 450 0.2 10 450

M 71+ 5 - 5.0 10 500 1.5 10 500

F 19-30 5 - 0.1 10 100 1.0 8 60

F 31-50 5 - 0.1 12 275 0.1 10 275

F 51-70 5 - 1.4 10 310 0.8 10 300

Pantothenate (mg)

F 71+ 5 - 5.0 10 110 0.7 10 110

M 19-30 700 4000 62 125 750 4 94 750

M 31-50 700 4000 50 125 210 2 62 210

M 51-70 700 4000 50 125 250 2 125 250

M 71+ 700 3000 50 125 265 2 125 265

F 19-30 700 4000 25 125 420 5 82 345

F 31-50 700 4000 25 125 500 2 103 500

F 51-70 700 4000 50 125 471 4 125 471

Phosphorus (mg)

F 71+ 700 3000 48 125 500 8 125 500

M 19-30 1.3 - 1.6 3.2 51 0.1 2.4 51

M 31-50 1.3 - 0.3 15 100 0.1 3.2 100

M 51-70 1.3 - 1.6 3.2 100 0.3 3.2 100

Riboflavin(mg)

M 71+ 1.3 - 0.8 3.2 100 0.7 3.2 148

24



DRI group RDA/AI UL


F 19-30 1.1 - 0.2 5 100 0.3 3.6 50

F 31-50 1.1 - 0.1 10 200 0.1 5.9 200

F 51-70 1.1 - 0.2 3.2 300 0.1 4.9 300

Riboflavin (mg)

F 71+ 1.1 - 1.2 3.2 100 0.1 3.2 100

M 19-30 1.2 - 1.2 2.2 52 0.1 2.1 54

M 31-50 1.2 - 0.9 15 100 0.2 2.2 100

M 51-70 1.2 - 1.2 2.2 101 0.2 2.2 101

M 71+ 1.2 - 0.8 2.2 100 0.4 2.2 148

F 19-30 1.1 - 0.6 4.5 100 0.2 4.1 50

F 31-50 1.1 - 0.1 15 200 0.1 5.9 200

F 51-70 1.1 - 0.3 3 300 0.1 4.9 300

Thiamin (mg)

F 71+ 1.1 - 1.2 2.2 100 0.1 2.2 100

M 19-30 900 30008 672 988 10320 32 909 10320

M 31-50 900 30008 255 2220 7500 16 983 6899

M 51-70 900 30008 375 1500 34880 22 1332 34880

M 71+ 900 30008 255 1332 7000 71 1332 7000

F 19-30 700 30008 289 1476 5690 29 970 5500

F 31-50 700 30008 56 1110 16500 32 988 16500

F 51-70 700 30008 255 1332 6000 49 1332 6000

Vitamin A (RAE)

F 71+ 700 30008 375 1332 7500 39 1332 7500

25



DRI group RDA/AI UL


M 19-30 1.3 100 2.0 5 51 0.1 2.8 51

M 31-50 1.3 100 0.5 5 200 0.1 3.0 200

M 51-70 1.7 100 2.0 8 102 0.3 6.5 102

M 71+ 1.7 100 1.0 5 125 0.3 5.0 148

F 19-30 1.3 100 0.3 6 100 0.3 4.3 55

F 31-50 1.3 100 0.1 8 200 0.1 5.0 200

F 51-70 1.5 100 0.4 8 400 0.2 7.1 300

Vitamin B6 (mg)

F 71+ 1.5 100 1.0 8 600 0.1 6.9 600

M 19-30 2.4 - 6.0 20 267 0.2 8.3 236

M 31-50 2.4 - 3.0 20 209 0.2 12 4849

M 51-70 2.46 - 6.0 24 510 1.0 16 436

M 71+ 2.46 - 3.0 25 1200 1.4 20 1200

F 19-30 2.4 - 1.7 18 232 0.9 12 184

F 31-50 2.4 - 0.8 20 3070 0.3 13 5999

F 51-70 2.46 - 2.0 25 9210 0.5 25 9210

Vitamin B12 (mcg)

F 71+ 2.46 - 2.0 25 1250 0.3 25 1100

M 19-30 90 2000 60 125 2150 3 90 2150

M 31-50 90 2000 81 650 2300 3 180 2116

M 51-70 90 2000 50 500 2722 16 230 2722

Vitamin C (mg)

M 71+ 90 2000 15 500 4200 5 391 4200

26


Table 3.7 (Cont’d)


DRI group RDA/AI UL


F 19-30 75 2000 50 180 2000 8 99 2171

F 31-50 75 2000 45 500 5145 3 209 4090

F 51-70 75 2000 20 500 9000 10 200 5320

Vitamin C (mg)

F 71+ 75 2000 50 120 12000 6 120 12000

M 19-30 200 2000 200 400 2400 5 286 2400

M 31-50 200 2000 36 400 1800 6 171 1343

M 51-70 400 2000 67 400 1400 7 381 1380

M 71+ 600 2000 85 400 1748 13 383 1748

F 19-30 200 2000 24 400 1400 1 263 874

F 31-50 200 2000 48 400 1200 9 279 1600

F 51-70 400 2000 50 400 1400 18 400 1720

Vitamin D (IU)

F 71+ 600 2000 50 400 2472 6 400 2472

M 19-30 1510 100011 6.7 34 311 0.2 20 454

M 31-50 1510 100011 16.8 40 670 0.1 27 670

M 51-70 1510 100011 20.1 268 1071 4.3 153 1071

M 71+ 1510 100011 6.7 268 1139 1.0 268 1139

F 19-30 1510 100011 6.7 34 733 0.9 20 1006

F 31-50 1510 100011 0.5 80 840 0.5 20 840

F 51-70 1510 100011 6.7 268 1097 3.3 268 1097

Vitamin E (eq)9

F 71+ 1510 100011 6.7 268 2412 0.4 268 2412

27


Table 3.7 (Cont’d)


DRI group RDA/AI UL


Zinc (mg) 11 40 7.5 15 90 0.1 11 90

M 31-50 11 40 0.4 15 60 0.1 6 60

M 51-70 11 40 5.0 15 108 0.2 15 100

M 71+ 11 40 1.1 15 100 0.7 15 100

F 19-30 8 40 0.3 15 150 0.7 13 150

F 31-50 8 40 0.6 15 68 0.2 9 68

F 51-70 8 40 0.3 15 55 0.3 15 50

F 71+ 8 40 1.0 15 75 1.0 15 75

M 19-30

Data obtained from BBCA E451311-011CV1 – Supplement Tables, Stephen Hayward, January 2003 1. RDA = Recommended Dietary Allowance 2. AI = Adequate Intake 3. UL = Tolerable Upper Intake Level 4. The UL for magnesium applies only to intake from supplements and pharmacologic agents 5. The UL for niacin and folic acid apply only to intake from supplements and fortified foods 6. Adults over 50 are advised to meet their RDA for vitamin B12 mainly by consuming fortified foods or a supplement 7. The RDA for folate is expressed as dietary folate equivalents (DFE), where 1 DFE = 1 µg food folate, or 0.6 µg from fortified food, or 0.5 µg from a

supplement taken on an empty stomach. 8. The UL for vitamin A applies only to intake from preformed retinol. 9. Vitamin E intakes from supplements are expressed as α-tocopherol equivalents. This older nomenclature also included a vitamin E value for tocopherols

other than α-tocopherol and for some tocotrienols, while the current RDA applies only to α-tocopherol 10. The RDA for vitamin E is expressed in mg α-tocopherol. This includes the RRR-α-tocopherol found in founds and the 2R stereoisomers that occur in

fortified foods and supplements. 11. The UL for vitamin E applies to any form of supplemental vitamin E (i.e., both the 2R and the 2S stereoisomers).

28


3.8 Effect of Supplement Intake on the Prevalence of Nutrient Inadequacy

The effect of supplement use on the prevalence of nutrient inadequacy among BC adults

is shown in Table 3.8 and Figure 3.2. This was assessed by comparing the proportions with

usual intakes below the EAR from food alone and from the combination of food plus

supplements. For all nutrients except niacin (which had a “zero” prevalence of inadequacy from

food alone) consideration of supplement use reduced the population prevalence of inadequacy,

although the reduction was not significant for thiamin, riboflavin, phosphorus and zinc.

Supplement use was associated with significant reductions in the population prevalence of

inadequacy for folate, vitamin B12 and vitamin C, and the differences approached significance

for vitamin B6 and magnesium. When the data were examined by sex and age group, similar

trends were observed, but in most cases, the differences were not significant because of broad

confidence intervals. However, supplement use significantly decreased the prevalence of dietary

folate inadequacy for women aged 31-50, 51-70, and 71 and above. Use of supplemental folic

acid also increased the proportion of women aged 19-50 who met the recommendation to

consume 400 mcg folic acid per day to prevent neural tube defects. No women met the

recommendation from food alone, compared to 16% from food plus supplements (data not

shown in Table).

29


Table 3.8 Effect of supplement use on the apparent prevalence (and 95% confidence interval) of nutrient inadequacy in BC adults

Men (age in years) Women (age in years) 19-30 31-50 51-70 >71 19-30 31-50 51-70 >71

All

Thiamin <EAR (food) 3%

(0,6) 0.7% (0,2)

5% (2,9)

3% (0.4,6)

7% (2,11)

14% (8,20)

14% (8,20)

5% (0.7,10)

7% (5,9)

<EAR (fd/supp) 2% (0,5)

0.5% (0,1)

4% (0.9,7)

1% (0.2,3)

5% (0,9)

11% (6,16)

7% (3,11)

1% (0,3)

5% (3,6)

Riboflavin <EAR (food) 3%

(0,7) 3%

(0,5) 3%

(0.5,5) 5%

(1,8) 2%

(0,5) 8%

(3,12) 4%

(0.2,8) 3%

(1,5) 4%

(3,5) <EAR (fd/supp) 2%

(0,5) 3%

(0,5) 3%

(0.3,5) 4%

(0.7,7) 2%

(0,5) 6%

(2,10) 0.5% (0,1)

1% (0.5,2)

3% (2,4)

Niacin <EAR (food) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) <EAR (fd/supp) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) 0%

(0,0) Vitamin B6 <EAR (food) 2%

(0.2,4) 0.3%

(0,0.8) 21%

(14,29) 19%

(12,25) 16%

(9,23) 19%

(13,25) 29%

(22,37) 36%

(26,45) 15%

(13,17) <EAR (fd/supp) 2%

(0,30 0.3%

(0,0.8) 19%

(12,26) 15%

(9,21) 13%

(6,19) 15%

(10,20) 16%#

(11,22) 20%

(12,28) 11%# (9,13)

Folate <EAR (food) 2%

(0,6) 5%

(2,8) 20%

(14,27) 35%

(26,44) 32%

(23,41) 40%

(33,47) 47%

(39,56) 67%

(58,76) 27%

(24,30) <EAR (fd/supp) 2%

(0,6) 3%

(1,5) 16%

(10,23) 27%

(18,36) 19%

(11,27) 23%*

(17,29) 29%*

(22,37) 39%*

(29,49) 17%*

(15,19) Vitamin B12 <EAR (food) 7%

(2,13) 10%

(5,16) 8%

(4,12) 13%

(6,19) 38%

(28,48) 25%

(18,32) 20%

(14,27) 18%

(11,25) 18%

(15,20) <EAR (fd/supp) 5%

(0.6,10) 9%

(4,14) 7%

(4,11) 12%

(5,18) 21%

(13,29) 16%

(11,22) 13%

(8,18) 10%

(4,15) 12%*

(10,14) Vitamin C <EAR (food) 31%

(22,41) 42%

(33,50) 34%

(26,43) 27%

(19,34) 33%

(24,42) 32%

(25,39) 20%

(13,26) 26%

(18,35) 32%

(29,35) <EAR (fd/supp) 25%

(16,35) 34%

(26,41) 26%

(18,34) 16%

(10,23) 23%

(15,32) 21%

(15,28) 11%

(5,16) 13%

(7,19) 23%*

(20,26) Magnesium <EAR (food) 32%

(21,42) 33%

(24,42) 44%

(35,53) 62%

(53,72) 37%

(28,46) 43%

(35,50) 40%

(32,48) 45%

(35,56) 39%

(36,43) <EAR (fd/supp) 31%

(20,41) 31%

(22,39) 37%

(28,45) 52%

(43,61) 31%

(22,39) 36%

(29,44) 27%

(19,34) 26%#

(18,35) 33%#

(29,36)

30


Table 3.8 (cont’d) Men (age in years) Women (age in years)

19-30 31-50 51-70 >71 19-30 31-50 51-70 >71 All

Phosphorus <EAR (food) 0.2%

(0,0.6) 0.2%

(0,0.6) 2%

(0,4) 0.1%

(0.0.2) 0.3%

(0,0.8) 2%

(0,5) 3%

(0.8,6) 2%

(0.5,4) 1%

(0.6,2) <EAR (fd/supp) 0.2%

(0,0.6) 0.2%

(0,0.6) 2%

(0,4) 0.1%

(0,0.2) 0.3%

(0,0.8) 2%

(0,5) 3%

(0.6,6) 2%

(0.5,4) 1%

(0.6,2) Zinc <EAR (food) 7%

(2,12) 11%

(6,17) 26%

(18,33) 42%

(34,51) 11%

(4,18) 11%

(6,15) 20%

(13,27) 19%

(11,27) 15%

(13,18) <EAR (fd/supp) 7%

(2,12) 11%

(5,16) 18%

(12,24) 33%

(24,41) 8%

(2,14) 10%

(5,15) 13%

(8,19) 10%

(5,15) 12%

(10,14) EAR = Estimated Average Requirement. The proportion of a group with usual intakes below the EAR approximates the population prevalence of inadequate intakes. * 95% Confidence intervals do not overlap; P < 0.05 # 95% Confidence intervals do not overlap, but upper boundary of CI for food alone is the same as lower boundary of CI for food plus supplements; significance thus approximates P = 0.05. Source: BBCA E451311-011CV1 – Supplement Tables, Stephen Hayward, January 2003

31


Figure 3.2. Prevalence of inadequate vitamin and mineral intakes from food alone, and food from plus supplements, among British Columbia adults.

#

0 5 10

Thiamin

Riboflavin

Niacin

Vitamin B6

Folate

Vitamin B12

Vitamin C

Magnesium

Phosphorus

Zinc

Food + Supplements

Supplement use significantly reVitamin B12 and folate (p<0.05vitamin B6 approached signific(Source: BBCA E451311-011C For nutrients that do n

supplement use on the prevalen

does not have an EAR, the d

requirement distribution is re

comparisons can be made that

supplements can be compared,

median intake meets or excee

15 20 25

Prevalence of inadequa

Food

duced the prevalence o), while the reduction iance (p~0.05).

V1 – Supplement Tab

ot have an EAR (cal

ce of inadequacy cann

istribution of requirem

quired to assess the p

may provide some insi

as a population can b

ds the AI. This is pa

30

cy (%)

f inaden inade

les, Ste

cium a

ot be q

ents is

revalen

ght. Fi

e assum

rticular

35 4

quate intakquate intak

phen Hayw

nd pantoth

uantitativel

not known

ce of inad

rst, median

ed to hav

ly true whe

0 45

es of Vitamin C, es of magnesium and

ard, January 2003)

enic acid), the effect of

y assessed. (If a nutrient

, and knowledge of the

equacy.) However, two

intakes with and without

e adequate intakes if the

n the AI was set as the

32


median intake of a healthy population, which is the case for pantothenic acid but not for calcium.

Second, the proportion of the population with intakes that meet the AI can be examined.

Although an intake below the AI cannot be assumed to be inadequate, intakes at or above the AI

can be assumed to be adequate.

Tables 3.9 and 3.10 provide data on the effect of supplement use on calcium intakes of

BC adults. As shown in Table 3.9, supplement use increased median intakes in all age/sex

groups, but in no case did it change the median intake from below the AI to at or above the AI.

Young men were the only age group with a median intake that met the AI, and this occurred

whether or not supplement use was considered.

Table 3.9 Effect of supplement use on median usual calcium intakes of BC adults Age/sex group Adequate Intake

(mg/d) Median Intake, Food


plus Supplements (mg/d)

Men 19-30 yr 1000 1044 1050 31-50 yr 1000 883 906 51-70 yr 1200 772 885 >71 yr 1200 727 847 Women 19-30 yr 1000 761 852 31-50 yr 1000 679 827 51-70 yr 1200 667 863 >71 yr 1200 662 948 Source: BBCA E451311-011CV1 – Supplement Tables, Stephen Hayward, January 2003

Table 3.10 shows the impact of supplement use on the proportion of adults with calcium

intakes at or above the AI. For men aged 50 or less, supplement use had essentially no impact on

the proportion meeting the AI, although for older men, there were modest increases. In contrast,

consideration of supplement use increased the proportion of women of all ages that met the AI.

33


This was particularly apparent for those over the age of 50, among whom the proportions

meeting the AI increased from 4% to 40% (age 51-70) and from 8% to 44% (age >71).

Table 3.10 Effect of supplement use on the proportion of BC adults meeting the adequate intake (AI) for calcium Age/sex group Adequate Intake

(mg/d) Proportion Meeting

AI from Food Proportion Meeting AI from Food plus

Supplements Men 19-30 yr 1000 53% 54% 31-50 yr 1000 42% 42% 51-70 yr 1200 12% 19% >71 yr 1200 9% 22% Women 19-30 yr 1000 26% 33% 31-50 yr 1000 13% 31% 51-70 yr 1200 4% 40% >71 yr 1200 8% 44% Source: BBCA E451311-011CV1 – Supplement Tables, Stephen Hayward, January 2003 Similar comparisons are made in Tables 3.11 and 3.12 for pantothenic acid. Table 3.11

shows that median intakes of men were at or above the AI whether or not supplement use was

considered. In contrast, women’s median intakes increased from below the AI to meet or almost

meet the AI when supplements were considered. Table 3.12 shows that consideration of

supplement use increased the proportions who met the AI for all age/sex groups, and that the

increases were greater in women than men.

34


Table 3.11 Effect of supplement use on the median usual pantothenic acid intakes of B.C. adults Age/sex group Adequate Intake



plus Supplements (mg/d)

Men 19-30 yr 5 6.7 7.1 31-50 yr 5 5.6 5.9 51-70 yr 5 5.3 6.0 >71 yr 5 4.9 5.4 Women 19-30 yr 5 4.0 4.9 31-50 yr 5 4.0 5.0 51-70 yr 5 4.2 5.0 >71 yr 5 3.9 4.6 Source: BBCA E451311-011CV1 – Supplement Tables, Stephen Hayward, January 2003 Table 3.12 Effect of supplement use on the proportion of BC adults meeting the adequate intake (AI) for pantothenic acid Age/sex group Adequate Intake

(mg/d) Proportion Meeting

AI from Food Proportion Meeting AI from Food plus

Supplements Men 19-30 yr 5 81.3% 85.1% 31-50 yr 5 73.0% 77.9% 51-70 yr 5 58.5% 66.7% >71 yr 5 48.8% 59.5% Women 19-30 yr 5 19.7% 48.0% 31-50 yr 5 20.8% 49.3% 51-70 yr 5 19.5% 49.8% >71 yr 5 15.0% 45.5% Source: BBCA E451311-011CV1 – Supplement Tables, Stephen Hayward, January 2003 3.9 Effect of Supplement Use on the Prevalence of Excessive Intakes In addition to reducing the prevalence of inadequate nutrient intakes, supplement use can

increase the potential risk of adverse effects from excessive intakes, and this can be assessed by

examining the prevalence of intakes that exceed the Tolerable Upper Intake Level (UL). (Note

that this could not be assessed for vitamin A, as the UL applies to preformed retinol only, and

35


these values were not available in the BCNS). As shown in Table 3.13, the prevalence of intakes

above the UL was close to zero for most nutrients for both men and women when intakes from

food alone were considered. Supplement use was associated with a substantial prevalence of

intakes above the UL for niacin (10-37%, depending on age/sex group). The adverse effect

associated with excessive intakes of niacin is flushing, which although uncomfortable, does not

appear to be medically dangerous and is easily terminated by reducing or stopping the

supplement dose (6). Supplement use was associated with smaller increases in the prevalence of

intakes above the UL for calcium, vitamin B6, folic acid, vitamin C, vitamin E, iron and zinc (<1

– 7%). Although the prevalence of intakes above the UL for vitamin B6 was relatively low, it is

nevertheless of potential concern since the adverse effect (peripheral neuropathy) is serious and

may not be reversible. The finding that depending on the age/sex group, between 2% and 7% of

BC adults were above the UL for folic acid also warrants comment. Here, the concern is that

excessive folate intakes may mask development of vitamin B12 deficiency. However, 84% of

those with folic acid intakes above the UL were also using a vitamin B12 supplement, suggesting

that very few individuals are at risk of deficiency.

36


Table 3.13 Effect of supplement use on the prevalence of BC adults with usual intakes above the tolerable upper intake level (UL) Men Women Nutrient

Age group (yr)

UL (mg/d)

>UL, food alone (%)

>UL, food and supplements

(%)

>UL, food alone (%)


(%) Calcium 19-30 2500 1 1 0 <1 31-50 2500 0 0 0 0 51-70 2500 0 0 0 3 >71 2500 0 0 0 1 Folic acid1 19-30 1 0 3 0 4 31-50 1 0 4 0 4 51-70 1 0 2 0 5 >71 1 0 7 0 5

Iron 19-30 45 0 1 0 3 31-50 45 0 <1 0 3 51-70 45 0 <1 0 0 >71 45 0 5 0 1

Niacin1 19-30 35 N/A 10 N/A 11 31-50 35 N/A 12 N/A 20 51-70 35 N/A 12 N/A 27 >71 35 N/A 19 N/A 37

Phosphorus 19-30 4000 <1 <1 0 0 31-50 4000 0 0 0 0 51-70 4000 0 0 0 0 >71 3000 <1 <1 0 0 Vitamin B6 19-30 100 0 0 0 0 31-50 100 0 <1 0 3 51-70 100 0 2 0 5 >71 100 0 2 0 5

Vitamin C 19-30 2000 0 2 0 <1 31-50 2000 0 <1 0 3 51-70 2000 0 1 0 2 >71 2000 0 1 0 1

37


Table 3.13 (Cont’d) Men Women Nutrient

Age group (yr)

UL (mg/d)

>UL, food alone (%)


(%)

>UL, food alone (%)


(%) Vitamin E2 19-30 1000 N/A 0 N/A <1 31-50 1000 N/A 0 N/A 0 51-70 1000 N/A <1 N/A <1 >71 1000 N/A 1 N/A 0

Zinc 19-30 40 0 4 0 3 31-50 40 <1 2 0 1 51-70 40 3 6 <1 3 >71 40 0 6 0 6 1. The UL for niacin and folate apply only to intake from supplements and/or fortified foods. For niacin, data on intake from fortified foods were not available. 2. The UL for vitamin E applies only to intake from supplements. 3.10 Other Supplements Used

Table 3.14 shows the proportions of BC adults who took one or more non-vitamin-

mineral supplements on the day before the survey and in the previous month. Overall, just over

a fifth had used a supplement yesterday, while about one-third had used a supplement during the

previous month. Confidence intervals were not available for these data, so the significance of

differences between sexes and across age groups cannot be determined. However, it appears that

women were somewhat more likely than men to have taken a non-vitamin-mineral supplement,

and that the prevalence of use tended to increase with age.

These observations are generally similar to those of a survey of members of a group

health maintenance organization in northern California, among whom 33% had used at least one

non-vitamin-mineral supplement during the past year (13). In that survey, use of all non-

vitamin-mineral supplements was highest among women aged 45-64 years of age who were

college graduates.

38


Table 3.14 Percent of BC adult population using non-vitamin-mineral supplements Supplement Consumed Sex/Age Group

Yesterday (%) Past Month (%) Men 19 – 30 yr 11 22 31 – 50 yr 16 25 51 – 70 yr 22 32 >71 yr 36 41

Women 19 – 30 yr 15 28 31 – 50 yr 20 38 51 – 70 yr 45 49 >71 yr 42 44

All Men and Women 22 33 Data from: BBCA Technical Document E451313-011C V3

A wide variety of non-vitamin/mineral supplements was used by study participants, and

these are listed in Table 3.15. The most commonly-cited substances were glucosamine and/or

chondroitin sulfate, garlic, various oils, echinacea and gingko biloba. In the Food Habits of

Canadians Study, the most frequently-cited non-vitamin-mineral supplements were garlic, an

herbal mix, evening primrose oil and Echinacea (4), while in the study of members of a health

maintenance organization in California, echinacea, gingko biloba and glucosamine were the most

frequently used products (13).

39


Table 3.15 Other supplements used by participants in the BC Nutrition Survey

Type of supplement Number using Glucosamine and/or chondroitin sulfate 208 Garlic 141 Oils (including flaxseed, evening primrose, oil blends, gamma-linolenic acid, borage)

125

Echinacea 121 Gingko biloba 112 Lecithin 57 Ginseng 45 Coenzyme Q10 43 Greens 37 St. John’s Wort 36 Lactic acid bacteria 34 Algae 34 Saw palmetto 25 Protein or amino acids 22 Grape seed extract 22 Cayenne 15 Cranberry 13 Prostate care 11 Devil’s claw 8 Milk thistle 7 Alfalfa 7 Royal jelly 7 Kava kava 7 Creatine monohydrate 6 Bee pollen 5 Other (unspecified) 308 Other (used by <4) 37 Data from: BBCA Technical Document E451313-011C V3References. Unweighted data. A discussion of the potential health benefits and/or adverse effects of these substances is

beyond the scope of this report. However, the potential of some of these products to interact

with certain prescription medications has been recognized (14-16), suggesting that it is important

for health professionals to ascertain their use by patients.

40


4.0 CONCLUSIONS

Data obtained in the British Columbia Nutrition Survey indicate that supplement use is

common among BC adults, particularly among seniors and women. The high prevalence of

supplement use emphasizes the importance of considering the contribution of supplements when

assessing dietary intake, whether that assessment is occurring at an individual level (e.g., a

dietitian assessing a client’s diet) or at a population level (e.g., using survey data to formulate

public policy recommendations). In the BCNS, consideration of supplement use reduced the

population prevalence of inadequacy for all nutrients except niacin (which had a “zero”

prevalence of inadequacy from food alone). Although the reductions were not significant for

thiamin, riboflavin, phosphorus and zinc, significant reductions were observed in the population

prevalence of inadequacy for folate, vitamin B12 and vitamin C, and the differences approached

significance for vitamin B6 and magnesium. The impact of supplementation of nutrient

adequacy cannot be quantitatively assessed for nutrients (such as calcium) that have an AI rather

than an EAR. However, use of calcium supplements did increase the proportions of individuals

(especially women) with intakes at or above the AI, although it did not increase median intakes

to meet the AI.

The new Dietary Reference Intakes reflect advances in our knowledge of nutrient

physiology and the role of nutrients in chronic disease prevention. In the past, dietary guidance

was based on the assumption that healthy individuals consuming a varied diet could meet all

their nutrient needs through food alone, and that supplementation was therefore not required.

Given current levels of fortification of the Canadian food supply, this assumption no longer

applies to some nutrients and some age/sex groups. Specifically, the DRIs recommend that all

women of child-bearing potential obtain 400 mcg of folic acid per day, and that adults over the

41


age of 50 obtain the majority of their RDA for vitamin B12 through synthetic sources.

Furthermore, although a specific recommendation for supplementation is not made, for practical

purposes most adults over the age of 50 will require a supplement to meet the AI for vitamin D.

In the BCNS, most individuals to whom these recommendations apply were not using the

appropriate supplement. Future dietary guidance may therefore need to include advice on

supplement use. In this regard, there may be a need to develop effective methods of educating

the public about supplements.

In addition to recognizing the positive contributions of supplements, it is also important

to consider their potential to lead to excessive nutrient intakes. In the BCNS, the prevalence of

nutrient intakes above the UL increased when supplement use was considered. In many cases,

the increases were modest (e.g., from 2% with diet alone to 5% with supplements), and although

the prevalence of excessive intakes of niacin was high at 10-37%, the health implications do not

appear to be serious. Nevertheless, particularly if current trends in supplement use continue,

monitoring this situation is warranted, as excessive intakes of some nutrients are associated with

serious and/or irreversible adverse effects.

Supplements used by BC adults included a wide variety of substances other than vitamins

and minerals. Because some of these substances interact with prescription medications, it may

become increasingly important for health professionals to inquire about their clients’ use of these

supplements.

42


5.0 REFERENCES 1. British Columbia Ministry of Health Planning. British Columbia Nutrition Survey: Nutrient

Report. Victoria BC: Ministry of Health Planning, 2004.

2. Balluz LS, Kieszak SM, Philen RM, Mulinare J. Vitamin and mineral supplement use in the

United States. Results from the Third National Health and Nutrition Examination Survey.

Arch Fam Med 2000;9:258-262.

3. Kaufman DW, Kelly JP, Rosenberg L, Anderson TE, Mitchell AA. Recent patterns of

medication use in the ambulatory adult population of the United States. The Slone Survey.

JAMA 2002;287:337-344.

4. Troppmann L, Johns T, Gray-Donald K. Natural health product use in Canada. Can J Public

Health 2002;93:426-430.

5. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Calcium,

Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington DC: National Academy

Press, 1997.

6. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin,

Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline.

Washington DC: National Academy Press, 1998.

7. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin C,

Vitamin E, Selenium, and Carotenoids. Washington DC: National Academy Press, 2000.

8. Food and Nutrition Board, Institute of Medicine Dietary Reference Intakes for Vitamin A,

Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum,

Nickel, Silicon, Vanadium, and Zinc. Washington DC: National Academy Press, 2001.

43


9. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Energy,

Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids

(Macronutrients). Washington DC: National Academy Press, 2002.

10. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes. Applications in

Dietary Assessment. Washington DC: National Academy Press, 2000.

11. Webb AR, Kline L, Holick MF. Influence of season and latitude on the cutaneous synthesis

of vitamin D3: exposure to winter sunlight in Boston and Edmonton will not promote vitamin

D3 synthesis in human skin. J Clin Endocrinol Metab 1988;67: 373-378.

12. Rucker D, Allan JA, Fick GH, Hanley DA. Vitamin D insufficiency in a population of

healthy western Canadians. Can Med Assoc J 2002;166:1517-1524.

13. Schaffer DM, Gordon NP, Jensen CD, Avins AL. Nonvitamin, nonmineral supplement use

over a 12-month period by adult members of a large health maintenance organization. J Am

Diet Assoc 2003;103:1500-1505.

14. Abebe W. An overview of herbal supplement utilization with particular emphasis on possible

interactions with dental drugs and oral manifestations. J Dent Hygiene 2003; 77(1):37-46.

15. Tessier DJ, Bash DS. A surgeon's guide to herbal supplements. J Surg Res 2003;114:30-36.

16. Dasgupta A. Review of abnormal laboratory test results and toxic effects due to use of herbal

medicines. Am J Clin Pathol 2003;120:127-137.

44

Ministry of Health - British Columbia Nutrition Survey: Report on Supplements · 2019-04-24 ·...

Documents

Transcript of Ministry of Health - British Columbia Nutrition Survey: Report on Supplements · 2019-04-24 ·...