Future research needs

17.8 Future research needs

To facilitate the implementation of a food-based approach in the pre- vention of micronutrient deficiencies the following research needs were identified:

• food data system development, which includes development of a method-

ology for micronutrient composition of foods, organizing data retrieval, and reporting and dissemination through electronic means; this effort should include phytochemicals, antioxidants, and other components which may affect health and nutrition, with special emphasis on local foods which may be important for given cultures;

• identification and evaluation of optimal methods for cooking foods to pre-

serve the nutrient value and enhance the bioavailability of micronutrients; • development of better methods to preserve foods, especially micronutrient-rich foods, at the household and community levels; • identification and propagation of agricultural methods which will enhance the yield, content, and biological value of micronutrient-rich foods; • identification of optimal food combinations and serving size which will be

most effective in preventing micronutrient deficits and methods of pro- motion for these food combinations at the community level;

• development of agricultural research to support the implementation of FBDGs;

VITAMIN AND MINERAL REQUIREMENTS IN HUMAN NUTRITION

• evaluation of the nutritional impact and cost–benefit of food-based approaches in combating micronutrient deficiencies.

References

1. Preparation and use of food-based dietary guidelines. Report of a Joint FAO/WHO Consultation. Geneva, World Health Organization, 1996 (WHO Technical Report Series, No. 880).

2. Oyarzun MT, Uauy R, Olivares S. Food-based approaches to improve vitamin and mineral nutrition adequacy. Archivos Latinoamericanos de Nutricion (Guatemala), 2001, 51:7–18.

3. Requirements of vitamin A, iron, folate and vitamin B 12 . Report of a Joint FAO/WHO Expert Consultation. Rome, Food and Agriculture Organization of the United Nations, 1988 (FAO Food and Nutrition Series, No. 23).

4. Olson JA. Needs and sources of carotenoids and vitamin A. Nutrition Reviews, 1994, 52(Suppl. 2):S67–S73.

5. Preventing micronutrient malnutrition: a guide to food-based approaches. Washington, DC, International Life Sciences Institute Press, 1997.

6. Trace elements in human nutrition. Geneva, World Health Organization, 1996.

7. Lotfi M et al. Micronutrient fortification of foods. Current practices, research, and opportunities. Ottawa, The Micronutrient Initiative, and Wageningen, International Development Research Center/International Agricultural Center, 1996.

8. Viteri FE. Prevention of iron deficiency. In: Howson CP, Kennedy ET, Horwitz A, eds. Prevention of micronutrient deficiencies. Tools for policy- makers and public health workers. Washington, DC, National Academy Press, 1998, 3:45–102.

9. Hallberg L, Hulthén L, Gramatkovski E. Iron absorption from the whole diet in men: how effective is the regulation of iron absorption? American Journal of Clinical Nutrition, 1997, 66:347–356.

10. Allen LH, Ahluwalia N. Improving iron status through diet. The application of knowledge concerning dietary iron bioavailability in human populations. Arlington, VA, John Snow, and Opportunities for Micronutrient Interven- tions Project, 1997.

11. Stanbury JB. Prevention of iodine deficiency. In: Howson CP, Kennedy ET, Horwitz A, eds. Prevention of micronutrient deficiencies. Tools for policy- makers and public health workers. Washington, DC, National Academy Press, 1998, 5:167–201.

12. Sullivan KM et al., eds. Monitoring universal salt iodization programs. Ottawa, The Micronutrient Initiative, 1995.

13. Tucker KL et al. Folic acid fortification of the food supply. Potential benefits and risk for the elderly population. Journal of the American Medical Associa- tion, 1996, 2776:1879–1885.

14. Oakley GP, Adams MJ, Dickinson CM. More folic acid for everyone, now. Journal of Nutrition, 1996, 126(Suppl.):S751–S755.

15. Bower C. Folate and neural tube defects. Nutrition Reviews, 1995, 53(Suppl. 2):S33–S38.

16. Daly S et al. Minimum effective dose of folic acid for food fortification to prevent neural-tube defects. Lancet, 1997, 350:1666–1669.

17. FOOD AS A SOURCE OF NUTRIENTS

17. International Conference on Nutrition. World Declaration and Plan of Action for Nutrition, 1992. Rome, Food and Agriculture Organization of the United Nations, 1992.

18. Diet, nutrition, and the prevention of chronic diseases. Report of a WHO Study Group. Geneva, World Health Organization, 1990 (WHO Technical Report Series, No. 797).

VITAMIN AND MINERAL REQUIREMENTS IN HUMAN NUTRITION

Annex 1

Recommended nutrient intakes a — minerals

Zinc c (mg/day)

Moderate Low Group

Calcium b Selenium Magnesium

High

(mg/day) (mg/day)

(mg/day)

bioavailability bioavailability bioavailability

Infants

0–6 months 300 d 6 26 d 1.1 d 2.8 6.6

400 g 36 h

7–12 months 400 10 54 0.8 d 4.1 8.4

2.5 j

Children

1–3 years 500 17 60 2.4 4.1 8.3 4–6 years

Females 10–18 years

4.3 7.2 14.4 Males 10–18 years

Females 19–50 years

3.0 4.9 9.8 (premenopausal) 51–65 years

3.0 4.9 9.8 (menopausal) Males 19–65 years

Females 65+ years

3.0 4.9 9.8 Males 65+ years

Pregnant women

First trimester m

3.4 5.5 11.0 Second trimester

4.2 7.0 14.0 Third trimester

Lactating women

a Recommended nutrient intake (RNI) is the daily intake which meets the nutrient requirements of almost all b (97.5%) apparently healthy individuals in an age- and sex-specific population.

c See Chapter 4 for details. d See Chapter 12 for details. e Breastfed. Neonatal iron stores are sufficient to meet the iron requirement for the first 6 months in full-term infants.

f Premature infants and low birth weight infants require additional iron. g Recommendation for the age group 0–4.9 years. h Cow milk-fed. Formula-fed.

ANNEX 1

Iron (mg/day)

5% Iodine Bioavailability

Bioavailability (mg/day) e e e e 90 f

18.6 i 90 f

3.9 4.8 5.8 11.6 90 f 4.2 5.3 6.3 12.6 90 f

5.9 7.4 8.9 17.8 120 (6–12 yrs) 9.3 (11–14 yrs) l

28.0 (11–14 yrs) l 150 (13–18 yrs) 21.8 (11–14 yrs)

11.7 (11–14 yrs) l

14.0 (11–14 yrs) l

65.4 (11–14 yrs) 20.7 (15–17 yrs)

27.7 (11–14 yrs)

32.7 (11–14 yrs)

62.0 (15–17 yrs) 9.7 (11–14 yrs)

25.8 (15–17 yrs)

31.0 (15–17 yrs)

29.2 (11–14 yrs) 150 (13–18 yrs) 12.5 (15–17 yrs)

Bioavailability of dietary iron during this period varies greatly.

Not applicable to infants exclusively breastfed.

Particularly during the growth spurt. m Pre-menarche.

Not specified. It is recommended that iron supplements in tablet form be given to all pregnant women because of the difficulties in correctly assessing iron status in pregnancy. In non-anaemic pregnant women, daily supplements of 100 mg of iron (e.g. as ferrous sulphate) given during the second half of pregnancy are adequate. In anaemic women higher doses are usually required.

VITAMIN AND MINERAL REQUIREMENTS IN HUMAN NUTRITION

Annex 2

Recommended nutrient intakes a — water- and fat-soluble vitamins

Water-soluble vitamins Vitamin C b Thiamine Riboflavin

Niacin c Vitamin B 6 Pantothenate Group

(mg/day) (mg/day) (mg/day) (mg NE/day) (mg/day) (mg/day)

1–3 years 30 0.5 0.5 6 0.5 2.0 4–6 years

Females 10–18 years

40 1.1 1.0 16 1.2 5.0 Males 10–18 years

Adults

Females 19–50 years

45 1.1 1.1 14 1.3 5.0 (premenopausal) 51–65 years

45 1.1 1.1 14 1.5 5.0 (menopausal) Males 19–65 years

45 1.2 1.3 16 1.3 (19–50 yrs) 5.0 1.7 (50+ yrs)

Elderly

Females 65+ years

45 1.1 1.1 14 1.5 5.0 Males 65+ years

Pregnant women

Lactating women

70 1.5 1.6 17 2.0 7.0 a Recommended nutrient intake (RNI) is the daily intake which meets the nutrient requirements of almost all

b (97.5%) apparently healthy individuals in an age- and sex-specific population. c See Chapter 7 for details. d NE = Niacin equivalents. DFE = Dietary folate equivalents; mg of DFE provided = [mg of food folate + (1.7 ¥ mg of synthetic folic

e acid)]. f Recommended safe intakes as mg retinol equivalent (RE)/day; conversion factors are as follows: Vitamin A values are “recommended safe intakes” instead of RNIs. See Chapter 2 for further details.

1 mg retinol = 1 RE 1 mg b-carotene = 0.167 mg RE 1 mg other provitamin A carotenoids = 0.084 mg RE.

ANNEX 2

Water-soluble vitamins Fat-soluble vitamins Biotin

Vitamin D Vitamin E g Vitamin K h (mg/day)

Vitamin B 12 Folate d Vitamin A e,f

(mg/day) (mg DFE/day) (mg RE/day) (mg/day) (mg a-TE/day) (mg/day)

5 (19–50 yrs) 10.0 65 10 (51–65 yrs)

5 j 55 g Data were not strong enough to formulate recommendations. The figures in the table therefore

850

h represent the best estimate of requirements.

See Chapter 6 for details.

Preformed niacin. k See Chapter 5 for details. This intake cannot be met by infants who are exclusively breastfed. To prevent bleeding due to vitamin

K deficiency, all breast-fed infants should receive vitamin K supplementation at birth according to

nationally approved guidelines. Not specified.