Micronutrient Facts

What to know

Micronutrients, often referred to as vitamins and minerals, are vital to healthy development, growth, disease prevention, and well-being. Here are six essential micronutrients and why they are important to our health.

Pregnant woman sitting on floor with preschool age child standing next to her.

Overview

With the exception of vitamin D, micronutrients are not produced in the body. People must get them from their diet.1

We only need small amounts of micronutrients. However, getting the recommended amount is important for health. Micronutrient deficiencies can have devastating consequences. At least half of children worldwide under 5 years old suffer from vitamin and mineral deficiencies.2 The World Health Organization recommends multiple interventions to address nutrition deficiencies.3

Iron

Students in classroom taking notes in notebooks.
Preventing iron deficiency helps improve children's learning ability.

Iron is important for motor development and helps develop the brain of a fetus and child. Children and pregnant women are especially vulnerable to the consequences of iron deficiency.3

Iron deficiency is a leading cause of anemia. Anemia is defined as low hemoglobin concentration. Globally, anemia affects 40% of children younger than 5 years old, and 30% of pregnant women.4

Anemia during pregnancy increases the risk of death for the mother and baby. Worldwide, maternal and neonatal deaths total between 2.5 million and 3.4 million each year.5 Additionally, anemia during pregnancy increases the risk of poor fetal growth, preterm birth, or low birth weight for the infant.

Babies have different needs when it comes to iron depending on what they are fed (only breast milk, only formula, or a mix of breast milk and formula).

In addition, iron deficiency limits physical productivity and work capacity.

Iron fact sheet in English and Spanish.

Vitamin A

Vitamin A supports healthy eyesight and immune system functions. Children with vitamin A deficiency face an increased risk of blindness and death from infections such as measles and diarrhea.6

Globally, vitamin A deficiency affects an estimated 190 million preschool-age children6.

Providing vitamin A supplements to children ages 6 months up to 5 years is effective in reducing deaths from causes related to vitamin A deficiency.6

Vitamin A fact sheet in English and Spanish.

Vitamin D

Bodies make vitamin D from sunlight, but this varies based on geography, skin color, air pollution, and other factors. Also, sunlight exposure needs to be limited to avoid risk of skin cancer.

All children need vitamin D beginning shortly after birth.

Vitamin D helps the immune system resist bacteria and viruses.7

Vitamin D is required for muscle and nerve functions.7

Vitamin D builds strong bones by helping the body absorb calcium.7This helps protect older adults from osteoporosis.

Vitamin D deficiency causes bone diseases, including rickets in children and osteomalacia in adults.7

Available data suggest that vitamin D deficiency may be widespread globally.8

Vitamin D fact sheet in English and Spanish.

Iodine

Closeup photo of salt being poured into a measuring spoon.
Fortifying salt with iodine successfully increases iodine intake.

Iodine is required during pregnancy and infancy for the infant's healthy growth and cognitive development.9

Iodine content in most foods and beverages is low. Globally, an estimated 1.8 billion people have insufficient iodine intake.

Fortifying salt with iodine is a successful way to help people get enough iodine. About 86% of households worldwide use iodized salt.10 The amount of iodine added to salt can be increased or decreased. This means that people can get enough iodine in their diet even if they eat less salt.11

Experts recommend that pregnant and breastfeeding women take a daily supplement with 150 micrograms of iodine.1213 Women who are planning to become pregnant should take a daily iodine supplement at least 3 months before pregnancy12.

Iodine fact sheet in English and Spanish.

Folate

Woman looks happy with result of an at-home pregnancy test.
Folate is especially important before and during pregnancy.

Everyone needs folate (vitamin B9) to make new cells every day.

Folate is essential in the earliest days of fetal growth for healthy development of the brain and spine.14 Folic acid is another form of vitamin B9. Women of reproductive age need 400 micrograms of folic acid every day14.

Ensuring women get enough folate before getting pregnant can reduce neural tube defects such as spina bifida and anencephaly.14

Some ways to make sure women 15 to 49 get enough folic acid are providing supplements and fortifying foods such as wheat flour. These interventions reduce cases of neural tube defects and can help prevent neonatal deaths.15

Folate fact sheet in English and Spanish.

Zinc

Zinc promotes immune functions and helps people resist infectious diseases including diarrhea, pneumonia, and malaria.161718 Zinc is also needed for healthy pregnancies.16

Globally, 17.3% of the population is at risk for zinc deficiency due to dietary inadequacy.19 Up to 30% of people are at risk in some regions of the world.19

Providing zinc supplements:

  • Reduces the incidence of premature birth.19
  • Decreases childhood diarrhea and respiratory infections.19
  • Lowers the number of deaths from all causes.19
  • Increases growth and weight gain among infants and young children.19

Providing zinc supplements to children younger than 5 years appears to be a highly cost-effective intervention in low- and middle-income countries.2021

When children are about 6 months old, it is important to start giving them foods with zinc.

Zinc fact sheet in English and Spanish.

  1. Kraemer K, Badham J, Christian P, et al., eds. Micronutrients, Macro Impact: The story of vitamins and a hungry world. Basel, Switzerland: Sight and Life Press; 2015.
  2. UNICEF. The State of the World’s Children 2019. Children, Food and Nutrition: Growing well in a changing world. New York, NY: UNICEF; 2019.
  3. World Health Organization (WHO). Interventions. e-Library of Evidence for Nutrition Actions (eLENA). August 2011. Accessed January 17, 2024. https://www.who.int/tools/elena/overview
  4. WHO. WHO global anaemia estimates, 2021 edition. Accessed January 17, 2024. https://www.who.int/data/gho/data/themes/topics/anaemia_in_women_and_children
  5. Stevens GA, Finucane MM, De-Regil LM, et al. Global, regional, and national trends in haemoglobin concentration and prevalence of total and severe anaemia in children and pregnant and non-pregnant women for 1995-2011: a systematic analysis of population-representative data. Lancet Glob Health. 2013;1(1): e16–e25. doi: 10.1016/S2214-109X(13)70001-9
  6. WHO. Guideline: Vitamin A supplementation in infants and children 6–59 months of age. Geneva, Switzerland: WHO; 2011.
  7. National Institutes of Health, Office of Dietary Supplements. What is vitamin D and what does it do?. November 8, 2022. Accessed January 17, 2024. https://ods.od.nih.gov/factsheets/VitaminD-Consumer/
  8. Roth DE, Abrams SA, Aloia J, et al. Global prevalence and disease burden of vitamin d deficiency: a roadmap for action in low- and middle-income countries. Ann N Y Acad Sci. 2018;1430(1):44–79. doi: 10.1111/nyas.13968
  9. Andersson M, Karumbunathan V, Zimmermann MB. Global iodine status in 2011 and trends over the past decade. J Nutr. 2012;142(4):744–750. doi: 10.3945/jn.111.149393
  10. Iodine Global Network. What is being done internationally about iodine deficiency? January 2015. Accessed January 17, 2024. https://ign.org/latest/stories/what-is-being-done-internationally-about-iodine-deficiency/
  11. WHO. Iodization of salt for the prevention and control of iodine deficiency disorders. August 2011. Accessed January 17, 2024. https://www.who.int/tools/elena/interventions/salt-iodization
  12. Alexander E, Pearce E, Brent G, et al. 2017 Guidelines of the American Thyroid Association for the Diagnosis and Management of Thyroid Disease during Pregnancy and the Postpartum. Thyroid. doi: https://doi.org/10.1089/thy.2016.0457
  13. Council on Environmental Health. Iodine deficiency, pollutant chemicals, and the thyroid: New information on an old problem. Pediatrics. 2014;133(6):1163–1166. doi: 10.1542/peds.2014-0900
  14. Centers for Disease Control and Prevention, National Center on Birth Defects and Developmental Disabilities. About Folic Acid. Accessed January 17, 2024. https://www.cdc.gov/folic-acid/about/index.html
  15. Blencowe H, Cousens S, Modell B, et al. Folic acid to reduce neonatal mortality from neural tube disorders. Int J Epidemiol. 2010;39 Suppl 1(Suppl 1):i110–i121. doi: 10.1093/ije/dyq028
  16. Ackland ML, Michalczyk AA. Zinc and infant nutrition. Arch Biochem Biophys. 2016;611:51–57. doi: 10.1016/j.abb.2016.06.011
  17. Lassi ZS, Moin A, Bhutta ZA. Zinc supplementation for the prevention of pneumonia in children aged 2 months to 59 months. Cochrane Database Syst Rev. 2016 Dec 4;12(12):CD005978. doi: 10.1002/14651858.CD005978.pub3
  18. Liu E, Pimpin L, Shulkin M, et al. Effect of zinc supplementation on growth outcomes in children under 5 years of age. Nutrients. 2018;10(3):377. doi: 10.3390/nu10030377
  19. Wessells KR, Brown KH. Estimating the global prevalence of zinc deficiency: results based on zinc availability in national food supplies and the prevalence of stunting. PLoS One. 2012;7(11):e50568. doi: 10.1371/journal.pone.0050568
  20. Fink G, Heitner J. Evaluating the cost-effectiveness of preventive zinc supplementation. BMC Public Health. 2014;14:852. doi: 10.1186/1471-2458-14-852
  21. Brown KH, Hess SY, Vosti SA, et al. Comparison of the estimated cost-effectiveness of preventive and therapeutic zinc supplementation strategies for reducing child morbidity and mortality in sub-Saharan Africa. Food Nutr Bull. 2013;34(2):199–214. doi: 10.1177/156482651303400209