MICRONUTRIENT MALNUTRITION

Thirty percent of the world's population is affected by vitamin A, iron, or iodine deficiency, and almost all the world's population is folate deficient. Thus, the health of many millions of people are adversely affected by these micronutrient deficiencies.

DISEASES CAUSED BY MICRONUTRIENT DEFICIENCY

Vitamin A deficiency causes blindness and increased mortality among children. Iron deficiency causes anemia, especially in women, pregnant women, and children. This iron-deficiency anemia causes loss of IQ points in children and loss of productivity in adults. In some countries it is estimated that iron deficiency is responsible for a 3 percent decrease in gross national productivity. Iodine deficiency causes goiter and mental retardation in its severest form, and loss of IQ points at lower levels of deficiency. Folate deficiency causes anemia, especially in pregnant women; and it may additionally result in spina bifida and anencephaly, two of the most common birth defects, in offspring of folate-deficient women. Folate deficiency also appears to be a major contributor to heart attack, strokes, and colon cancer.

PREVENTING MICRONUTRIENT DEFICIENCY

The very good news is that there is technology in hand that can prevent at least 75 percent of micronutrient deficiency in the world, at a cost of about thirty-five cents (U.S.) a year.

Iodination of table salt can nearly eliminate iodine deficiency diseases. During the 1990s, concerted international efforts led to more than 75 percent of the world's population having iodine deficiency eliminated. This success was achieved because there was an understanding of the need to solve the iodine deficiency problem, the political will to solve the problem, an effective, cheap intervention available, and because strong and persistant individuals who advocated for the prevention of iodine deficiency diseases worked with industry and governments to eliminate iodine deficiency on a country-by-country basis.

Folic acid fortification of grains is a cheap and very effective way to eliminate folate deficiency. The United States has required that enriched grains contain 1.4 parts per million, an action that was followed within months by a near tripling of serum folates in the population. Fortification of wheat and corn flours around the world offer the possibility of eliminating folate deficiency for 75 percent of the world's population.

Fortification of flour with iron has also been shown to be a very effective way to increase blood-iron levels and to eliminate iron-deficiency anemia. Fortification of grains with iron can eliminate about 75 percent of the iron deficiency remaining in the world today. Fortification of infant formulas is an effective way to increase iron consumption among children.

Vitamin A is fat soluble. Sugar, margarine, milk, and edible oils can be fortified at sufficient level to lower vitamin A deficiency in a population. These foods should be fortified in countries where there is significant consumption. Research to identify even more foods to be fortified is needed to provide the technical basis to eliminate 75 percent of vitamin A deficiency. Genetically modified foods containing an increased amount of vitamin A is another promising approach to preventing vitamin A deficiency.

SUPPLEMENT STRATEGIES

Consumption of pills with vitamin A, iron, iodine, and folic acid are very effective and cost-effective ways to treat micronutrient diseases or to prevent micronutrient diseases. They are necessary where there is no widely consumed food that can be fortified, and before effective fortification of foods has been instituted in a country. Supplement strategies are also likely to be needed to complement fortification programs. People living in urban areas may be consuming foods that can be fortified, but rural people in the same country may not be consuming such foods and thus require a supplement strategy for prevention and cure. The downside of supplement programs is the difficulty in getting the population to consume supplements on a continuing basis. There has, however, been good success with once-a-year vitamin A programs and once-a-week programs for iron for women of reproductive age. Iron and folic acid supplements are also effective in preventing and treating folate-and iron-deficiency anemia of pregnancy. For many years, and without recommendations from the medical/nutritional establishment, 25 percent of American adults have regularly consumed multivitamin supplements. So it is clear that supplements can play a role in preventing and curing micronutrient malnutrition.

Eating a healthy diet is highly desirable and should be encouraged. Changing the foods eaten can make a contribution to preventing micronutrient deficiency. The problem with dietary diversity is that change is usually slow—with progress measured in years. This slowness is in sharp contrast to the instant change in consumption by fortification and supplement programs.

THE ELIMINATION OF MICRONUTRIENT DEFICIENCY

Smallpox was eradicated from the earth about two hundred years after the vaccine that provided the scientific basis for eradication was developed. It has been a little over fifty years since the polio vaccine was developed, and the elimination of polio from the world is in sight. The scientific understanding of the problem of iodine deficiency and an effective fortification strategy have existed for seventy years, and iodine deficiency may soon be obliterated. Vitamin A deficiency, iron deficiency, and folate deficiency have been known for seventy years, but only modest progress has been made to eliminate these micronutrient deficiencies. A concerted international effort could eliminate at least 75 percent of the world's population deficiencies of vitamin A, iron, and folate by 2010. The public health challenge is to create the political will to implement the effective strategies—especially fortification—to eliminate micronutrient deficiency.

Godfrey P. Oakley, Jr.

(see also: Foods and Diets; Nutrition )

Bibliography

Asian Development Bank (2000). Manila Forum 2000: Strategies to Fortify Essential Foods in Asia and the Pacific. Proceedings of a Forum on Food Fortification Policy for Protecting Populations in Asia and the Pacific from Mineral and Vitamin Deficiencies. Manila, Philippines: Asian Development Bank; Washington, DC: International Life Sciences Institute; Ottawa, ON: Micronutrient Initiative. Publication Stock No.090400.

National Academy of Science, Board on International Health, Food and Nutrition Board, and Institute of Medicine (1998). Prevention of Micronutrient Deficiencies: A Toolkit for Policymakers and Public Health Workers. Washington DC: National Academy Press. Available at http://www.nap.edu.