Calcium and vitamin D – Role in Musculoskeletal Health
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Transcript of Calcium and vitamin D – Role in Musculoskeletal Health
Calcium and vitamin D – Role in Musculoskeletal Health
Bess Dawson-Hughes, M.D.
How to understand the absorption of calcium correctly?
Calcium
Ca intake absorption Vitamin D
Ca++ Muscle str.
PTH Falls
Bone remodeling
Bone loss Fracture risk
Mechanisms of Intestinal Calcium Absorption
Hoenderop J, et al. Physiol Rev. 2005;85:373-422.
Bullamore R. Lancet 1970; 2: 535-7.
What is the calcium intake that leads to maximal calcium
retention in bone?
Forbes, 1979
Intake (mg/day)
% M
axim
al r
eten
tio
n
200
300
100
0
-100
Linda and George McCabe, Purdue University, with permission
300
200
100
0
-100
-200
0 500 1000 1500 2000 2500
Calcium absorption from different calcium salts were similar to whole milk
39
32 3230
2731
0
5
10
15
20
25
30
35
40
45
Carbonate Lactate Acetate Ci trate Gl uconate Whol e mi l k
Sheikh MS, et al. N Eng J Med,1987,317(9):532-6
Net
Cal
cium
abs
orpt
ion(
%)
Intestinal Absorption of Calcium from Different Calcium Salts
Harvey JA, et al. J Bone Miner Res 1988; 3: 253-8.
Calcium Absorption in Relation to Dose
Bo-Linn GW, et al. J Clin Invest,1984,73:640-7.
Calcium Absorption in Relation to Gastric Acid Secretion
Heaney RP, et al. Am J Clin Nutr 1989; 49: 372-6.
Calcium Absorption in Relation to Meal
Effect of Oral Amino Acids on Absorption of Calcium
Civitelli R et al. Nutrition 1992; 8(6):400-405
Amino acid chelated calcium & Carbonate calcium
Search: MEDLINE 2004-2006• • #1 0 osteoform• #2 30345 calcium• #3 0 osteoform and calcium• #4 64802 amino• #5 136334 acid• #6 172 chelated• #7 30345 calcium• #8 0 amino acid chelated calcium• #9 1531 carbonate• #10 30345 calcium• #11 583 carbonate calcium
•
Search: MEDLINE 1999-2003•
•#1 0 Osteoform
•#2 147398 amino
•#3 288313 acid
•#4 345 chelated
•#5 64534 calcium
•#6 0 amino acid chelated calcium
•#7 2473 carbonate
•#8 64534 calcium
•#9 855 carbonate calcium
Lead Content of Calcium Supplements
Supplement
category
Lead content, g/
800 mg calcium
Refined 0.92 0.56
Dolomite 4.17 2.02
Natural source 6.05 4.63
Bone meal 11.33 12.46
Milk 0.71 0.32
Borgoin BP, et al. Am J Pub Health 1993.
Effect of Increasing Calcium Intake on PTH and Bone Turnover in Women
Elderly Young
Normal Ca High Ca
Calcium Intake (mg/d)
813 2,414 918
PTH (pmol/L) 3.41a 2.18 2.01
Urine pyridinoline/Cr 51.7b 43.1 43.7
a Differs from other groups, p < 0.001
b Differs from other groups, p < 0.05
McKane WR et al. J Clin Endocrinol Metab 1996; 81(5):1699-1703.
Shea B, et al. Endocrine Rev . 2002,23(4):552-559.
Calcium Supplementation for the Prevention of Postmenopausal Osteoporosis : a meta-analysis
Calcium supplementation in women older than 45 yr with absence of menses for a minimum of 6 months; Treatment with doses of calcium at least 400 mg/d. The maintenance dose of vitamin D was no more than 400 IU/d
Weighted mean difference for lumbar spine after treatment with calcium at 2 yr.
Calcitonin, Calcium and Vertebral Fracture Risk – MEDOS Study
Kanis JA. Br Med J 1992; 305; 1124-28.
*
*P=0.01
0
0.5
1
Calcitonin Calcium Ca + Calcitonin
0.630.820.78
Ris
k R
atio
Fracture Prevention Trials: Calcium and Vitamin D Use and Results
Drug/Study Ca, mg/d Vit D, IU/dFracture risk
reduction (RR)
Alendronate
Liberman ‘95 500 0 0.5
Black ‘96 500* 250 0.5
Cummings ‘98 500* 250 0.6
Risedronate
Harris ‘99 1,000 500† 0.6
Raloxifene
Ettinger ‘99 500 400-600 0.7
* If dietary calcium < 1,000 mg † If 25(OH)D level < 40 nmol/L
Calcium Intake in Elderly Chinese Women
Vegetarian (N=179)
Omnivore (N=250)
Age 81.3 70.7
Calcium, mg/1000 kcal 328 221
Potassium, mg/1000 kcal 914 783
Woo J et al. Age and Ageing 1998; 27:455-461.
Magnesium – Research Progress
• Mg depletion studies have been done in rats.
• Several epidemiologic studies have found positive associations between magnesium intake and bone mass and negative associations with diabetes and stroke.
Magnesium Depletion and the Skeleton in Rats
Diet % Nutrient Requirement Outcome
50a ↓ trabec vol, ↑osteoclast #
25b also ↑TNF-alpha
10c also ↑TNF-alpha
a Rude R. OI 2006; on-line.b Rude, R. Bone 2005; 37:211-219.
c Rude R. J Nutr 2004; 134:79-85.
Magnesium Intake – Associations with Diabetes and Stroke
Diabetesa
In >100,000 subjects followed for 12 to 18 yrs: High vs. low quintile RR 0.66 [0.60 –
0.73]
Strokeb
In 43,738 men followed for 8 yrs:
High vs. low quintile RR 0.62 [0.43, 0.88]
a Lopez-Ridaura R et al. Diabetes Care 2004; 27(1):134-140.b Ascherio A et al. Circulation 1998; 98(12):1198-204.