STRUCTURE FOR CONSIDERINGMICRONUTRIENTS (VAD, IDD, IDA)

SITUATION

- what is the micronutrient and deficiency? - causes and consequences of deficiency - assessment methods - prevalences, trends, who is affected... - goals, monitoring of progress.

PREVENTION METHODS FOR DEFICIENCES - supplementation - fortification - dietary change - program planning and implementation - supporting policies and contextual factors - costs, effects, budget, finance.

RECENT PROGRESS AND OUTLOOK - trends in programs - trends in outcome - current and new policies and programs and unmet needs - emerging problems.

STRUCTURE FOR CONSIDERINGMICRONUTRIENTS (VAD, IDD, IDA)

MICRONUTRIENTS VITAMINS (essential organic compounds not synthesized in the body)

Fat soluble: A, E, K; essential fatty acids; 'vitamin D' function in membranes, antioxidants, hormones, transmitters.

Water soluble: B complex, C cofactors in metabolic pathways; maybe many others for C.

ESSENTIAL MINERALS (cannot be synthesized; electrolytes like sea water)

Macro (usually milligram daily needs): Ca, P, Na, K, Fe, Mg, Zn electrolyte balance; bone structure; active site -- haemoglobin, enzymes.

Micro (v small amounts essential) iodine: hormone constituent.

USEFUL SUBSTANCES DRAWN FROM DIETMany plant constituents still to be characterized: antioxidants, anti-cancer, probably other benefits.

Methods for assessing deficiencies of VA, iron, and iodine.

Deficiency Diet Biological outcome Function

Vitamin A VA-rich foodfrequencies, intakes (also fat)

Serum retinol Night blindnessEye damage (Bitot’s spots) Survival

Iron Haem iron intakeInhibitorsVitamin C

Haemoglobin (Hb)(Anaemia)

Physical work. Pregnancy/maternalhealth.Cognitive development andbehaviour

Iodine Iodized salt GoitreTSH

IQ. Schooling.Physical and mental vigour

Methods for assessing deficiencies of VA, iron, and iodine.

Deficiency Diet Biological outcome Function

Vitamin A VA-rich foodfrequencies, intakes (also fat)

Serum retinol Night blindnessEye damage (Bitot’s spots) Survival

Iron Haem iron intakeInhibitorsVitamin C

Haemoglobin (Hb)(Anaemia)

Physical work. Pregnancy/maternalhealth.Cognitive development andbehaviour

Iodine Iodized salt GoitreTSH

IQ. Schooling.Physical and mental vigour

Table 1. Indicators of micronutrient deficiencies as established by WHO

Vitamin A Iodine Iron

Clinical XerophthalmiaNight blindness (XN) inchildren 24-71 monthsof ageBitot’s spots (X1B)Sum (XN+X1B) usedhere

GoitreGrade 1=palpable notvisibleGrade 2=visible whenneck in normal position Sum (grades 1+2) usedhere.

AnemiaHb <12g/dl in non-pregnant women>15 yrs of ageHb <11g/dl in pregnant women ofany ageHb <13g/dl in men >15 yrs*Hb <11g/dl in children 6-60 monthsHb <11.5g/dl in children 5-11 yrs*Hb <12g/dl in children 12-14 yrs*

Sub-clinical

Retinol levelIn serum, <0.7 mcmol/l(=20mcg/dl)In breast milk,<1.05mcmol/l

Urinary iodine*Median (for population)<100 mcg/l

TSH (neonates)*Level > mU/l

Serum ferritin*

WHO – World Health Organization. Hb = haemoglobin. TSH – thyroid stimulating hormone.

Sources: Howson et al (1998a, table 2.1); for vitamin A, WHO (1996); for iodine, WHO (1994); for iron, WHO/UNICEF/UNU (1997).

* Indicator not used in this report.

Table copied from Mason et al, 2001, p.4 (The Micronutrient Report)

Table 1. Indicators of micronutrient deficiencies as established by WHO

Vitamin A Iodine Iron

Clinical XerophthalmiaNight blindness (XN) inchildren 24-71 monthsof ageBitot’s spots (X1B)Sum (XN+X1B) usedhere

GoitreGrade 1=palpable notvisibleGrade 2=visible whenneck in normal position Sum (grades 1+2) usedhere.

AnemiaHb <12g/dl in non-pregnant women>15 yrs of ageHb <11g/dl in pregnant women ofany ageHb <13g/dl in men >15 yrs*Hb <11g/dl in children 6-60 monthsHb <11.5g/dl in children 5-11 yrs*Hb <12g/dl in children 12-14 yrs*

Sub-clinical

Retinol levelIn serum, <0.7 mcmol/l(=20mcg/dl)In breast milk,<1.05mcmol/l

Urinary iodine*Median (for population)<100 mcg/l

TSH (neonates)*Level > mU/l

Serum ferritin*

WHO – World Health Organization. Hb = haemoglobin. TSH – thyroid stimulating hormone.

Sources: Howson et al (1998a, table 2.1); for vitamin A, WHO (1996); for iodine, WHO (1994); for iron, WHO/UNICEF/UNU (1997).

* Indicator not used in this report.

Table copied from Mason et al, 2001, p.4 (The Micronutrient Report)

DIET

VA: frequency of VA-rich foods by recall (e.g. 24 hr) – see Sommer 1995, Nepal. Best to internally compare.Iron: haem iron (red meats); semi-quantitative at best; bioavailability very variable and low (e.g. 5-15%); inhibitors

tannins (tea) and phytates (cereals).Iodine: iodized salt if endemic area (otherwise seafood).

BIOLOGICAL OUTCOME

Blood: VA: sample or dried blood spot for serum retinol by HPLC or (?) fluorimetry; RDR or MRDR, children.Hb: droplet of blood by HemoCue or similar method; women and children.TSH: blood spot immunoassay (expensive) on neonates.

Urine: Chemical analysis of iodine in urine casual sample: school age children.

Examination: Goitre, all ages.Night blindness and/or Bitot’s spots (XN/X1B): children and women.

0 20 40 60

Underweight

Anemia

VAD

IDD

Figure 13. Summary of estimated regional prevalences of underweight, anemia, vitamin A deficiency (sub-clinical), and IDDs, in pre-school children, c.1995 (see table 8 for data)

TABLE 23. Estimated reductions in the disease burden (% DALYs lost) in developing countries (all population groups, all causes), from children underweight or deficiencies of vitamin A (clinical), iodine (measured as goiter), and anemia; from the direct effect (the deficiency considered as a disease itself) and as a risk factor for other diseases (infectious diseases only included in estimating reduction).

Note: underweight refers to children 0-59 months, < - 2 SDs weight-for-age; vitamin A deficiency is calculated from clinical deficiency in children 0-59 months; anemia refers to women 15-49 years; IDDs refers to iodine deficiency disorders, all ages, calculated from goiter prevalences. Methods are given in the source. Source: Mason, Musgrove & Habicht, (2003), table 10: [39]

Direct effect As risk factor Total Child underweight 1.0% 14.0% 15.0% Vitamin A deficiency 1.0% 4.5% 5.5% Anemia 3.3% 0.3% 3.6% IDDs 4.7% 3.7% 8.4% Total 10.0% 22.5% 32.5%

CONTROLLING MICRONUTRIENT DEFICIENCIES

OPTIONS

- FORTIFICATION

- SUPPLEMENTATION

- DIETARY CHANGE

Diet Fortification Supplementation Other

IDD Reduce goitrogens Salt Oral iodized oil in extreme cases

Sterilize using I (milk, maybe water)

VAD Orange yellow fruits and vegetables.Red palm oilAnimal foodsBreast milk

SugarVegetable oilMany commercial products

Frequent low dose VAPhase out periodic VACs, except post delivery

DewormIncrease fat

Iron deficiency Vitamin CHaem ironAvoid tannins, phytates

Flour Try for riceSoy and fish sauces

Fe/folate or MMNs, daily/weeklyEspecially during pregnancy

Drink tea not during mealDelay cord cuttingFerric iron not much use. (nor is ‘enrichment’)

Strategy now …

Large scale programs

Effectiveness m&e, to build improvement and sustainability - VAC distribution - iodized salt

Trial/pilot -- Efficacy and acceptability research - VA fortification (esp. oil, otherwise with multi) - multi fortification of commercial foods - multi ‘sprinkles’ - multi supplementation esp. in pregnancy

Sequence of intervention development

Research and Development - iron fortification of staples, esp. rice - iron in salt