Micronutrient Facts

Vitamin A Iron Iodine Folic Acid

Vitamin A

"Improved vitamin A nutrition could prevent up to 2.5 million deaths annually among children under 5 years." Vitamin A for the Children of the World Task Force Sight and Life, 2000.

The problem of vitamin A deficiency

• Vitamin A deficiency causes night blindness and is the single most important cause of childhood blindness in developing countries. Every year, about 500,000 children lose their sight as a result of vitamin A deficiency. The majority (about 70%) die within one year of losing their sight.
• Vitamin A deficiency increases the risk of severe illness, and even death, from common childhood infections such as diarrheal diseases and measles. In developing countries 200–300 million children of preschool age are at risk of vitamin A deficiency.
• Vitamin A deficiency may increase the risk of maternal mortality in pregnant women. Nearly 600,000 women die from childbirth-related causes each year, the vast majority of them from complications which could be reduced through better nutrition, such as vitamin A.

Global Prevalence of Vitamin A Deficiency WHO/UNICEF 1995
Combating vitamin A deficiency. WHO 2002
http://www.who.int/nut/vad.htm*

Vitamin A for the Children of the World, Task Force Sight and Life, 2000
http://www.sightandlife.org/sightandlife/aaHTMallg/home2.html*

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Iron

"As many as 4–5 billion people, 66–80% of the world's population, may suffer from reduced learning ability and work capacity due to iron deficiency."
Battling iron deficiency anemia WHO 2002
http://www.who.int/nut/ida.htm*

Preventing iron deficiency helps improve children's learning ability and cognitive development.

The problem of iron deficiency

Iron deficiency, and specifically iron deficiency anemia, is one of the most severe and important nutritional deficiencies in the world. Preschool children and women of reproductive age are at highest risk. As many as 4–5 billion people, 66–80% of the world's population, may be iron deficient and approximately 2 billion people, more than 30% of the world's population, are anemic. It is estimated that more than half of the pregnant women in developing countries are anemic.

• Iron deficiency impairs the cognitive development of children through to adolescence.
• Iron deficiency damages immune mechanisms, and is associated with increased morbidity rates.
• Iron deficiency impairs physical work capacity in men and women by up to 30%.
• Iron deficiency during pregnancy is associated with multiple adverse outcomes for both mother and infant, including increased risk of sepsis, maternal mortality, perinatal mortality, and low birth weight.

Iron deficiency and anemia reduce learning ability and the work capacity of individuals and entire populations, bringing serious economic consequences and obstacles to national development.

Micronutrient Deficiencies Battling Iron Deficiency Anemia WHO 2002
http://www.who.int/nut/ida.htm*

Iron Deficiency Anaemia. Assessment, Prevention and Control. A Guide for Programme Managers. WHO/UNICEF/UNU 2001
http://www.who.int/nut/documents/ida_assessment_prevention_control.pdf* (PDF–580K) 
You will need Adobe Acrobat to view and print this file.

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Iodine

Iodine deficiency is the number one cause of preventable brain damage, affecting millions of people worldwide.

Assessment of Iodine Deficiency Disorders and Monitoring their Elimination: A Guide for Programme Managers 2nd edition. WHO/UNICEF/ICCIDD 2001
http://www.who.int/nut/documents/assessment_idd_
monitoring_eliminination.pdf* (PDF–1,237K) 
You will need Adobe Acrobat to view and print this file.

The problem of iodine deficiency

The problem of iodine deficiency is especially serious for pregnant women and young children. During pregnancy, even a mild deficiency of iodine can reduce brain development of the fetus limiting the intellectual ability of an individual for life.

• Iodine deficiency can cause severe mental and physical retardation, known as cretinism.
• Iodine deficiency in chronic form, can cause goiter (a disorder characterized by swelling of the thyroid gland) in both adults and children.
• Iodine deficiency most commonly, impedes fetal brain development. At the population level, the consequence of iodine deficiency is a 10–15% lower average intellectual quotient (IQ), which affects the social and economic development of both communities and nations.

The World Bank has estimated that, combined with vitamin A deficiency and iron deficiency, iodine deficiency may lower the economic wealth of a nation by as much as 5% every year.

Assessment of Iodine Deficiency Disorders and Monitoring their Elimination: A Guide for Programme Managers 2nd edition. WHO/UNICEF/ICCIDD 2001 
http://www.who.int/nut/documents/assessment_idd_
monitoring_eliminination.pdf* (PDF–1,237K) 
You will need Adobe Acrobat to view and print this file.

Network for Sustained Elimination of Iodine Deficiency
http://www.sph.emory.edu/iodinenetwork/index.html*

Ending Iodine Deficiency Forever. A goal within our grasp. UNICEF/WHO 2000
http://www.unicef.org/pubsgen/salt/idd.pdf* (PDF–1,236K) 
You will need Adobe Acrobat to view and print this file.

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Folic Acid

Folic acid helps prevent spina bifida and anencephaly that affect at least 225,000 children a year throughout the world.
Berry RJ et al. Prevention of Neural-tube Defects with Folic Acid in China. China-U.S. Collaborative Project for Neural Tube Defect Prevention. N Engl J Med 1999;341(20):1485–1490.

Flour can be fortified with folic acid at low cost, helping prevent birth defects and some forms of anemia.

The problem of folic acid deficiency

An estimated 300,000 children are born each year with spina bifida and anencephaly, which are severe neural tube defects. Approximately 75%, 225,000, of these affected births could be prevented through increased consumption of synthetic folic acid by all women of reproductive age.

• Folic acid can help prevent birth defects of the brain (anencephaly) and the spinal cord (spina bifida) called neural tube defects.
• Folic acid can help prevent anemia.
• Folic acid can possibly help prevent breast cancer, colon cancer and heart disease.

Berry RJ et al. Prevention of neural-tube defects with folic acid in China. China-U.S. Collaborative Project for Neural Tube Defect Prevention. N Engl J Med 1999;341(20):1485–1490.

MRC Vitamin Study Research Group Prevention of neural tube defects: results of the Medical Research Council Vitamin Study. MRC Vitamin Study Research group. Lancet 1991;338 (8760):131–7.

Czeizel AE, Dudas I: Prevention of the first occurrence of neural tube defects by periconceptional vitamin supplementation. N Engl J Med 1992;327(26):1832–5

Why Folic Acid is So Important. CDC 2002
http://www.cdc.gov/ncbddd/folicacid/

*Links to non-Federal organizations are provided solely as a service to our users. Links do not constitute an endorsement of any organization by CDC or the Federal Government, and none should be inferred. The CDC is not responsible for the content of the individual organization Web pages found at this link.

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This page last updated December 08, 2003

United States Department of Health and Human Services
Centers for Disease Control and Prevention
National Center for Chronic Disease Prevention and Health Promotion
Division of Nutrition and Physical Activity