Prepared by Francisca Soto-Aguilar Bralic. MD, Ms Nutrition, Ms Global Public Health
Zinc is an essential trace mineral that plays a key role in numerous biological processes, including immune function, protein synthesis, DNA synthesis, and cell division. Adequate zinc intake is crucial for proper growth, development, and immune health in children. Zinc deficiency can impair immune function, delay growth, and increase the risk of infections. This guideline provides evidence-based recommendations for zinc supplementation in children based on the U.S. Recommended Dietary Allowances (RDAs) and offers practical advice for healthcare professionals.
Recommended Dietary Allowances (RDA) for Zinc in Children
The U.S. Institute of Medicine (IOM) has established RDAs for zinc based on age and physiological status. The following table provides the RDA for zinc in children:
| Age Group | RDA (mg/day) | Upper Limit (UL) (mg/day) |
|---|---|---|
| 0-6 months | 2 | 4 |
| 7-12 months | 2 | 5 |
| 1-3 years | 2-5 | 7 |
| 4-8 years | 5 | 12 |
| 9-13 years | 8 | 23 |
| 14-18 years (males) | 11 | 34 |
| 14-18 years (females) | 9 | 34 |
Note: The RDA represents the intake level sufficient to meet the nutritional needs of nearly all healthy children.
Upper Limit (UL): The maximum daily intake that is unlikely to cause harmful effects for most people.
Zinc Supplementation Recommendations by Age
Infants (0-12 months)
Rationale: Zinc is important for growth, immune function, and proper development in infants. Breast milk typically provides sufficient zinc, but in cases of exclusive formula feeding or low birth weight, additional zinc may be required.
Recommendation:
- Infants aged 0-6 months: The RDA for zinc is provided adequately through breast milk or zinc-fortified formula.
- Infants aged 7-12 months: If breastfeeding, zinc levels in breast milk are typically sufficient unless the mother is zinc-deficient. Zinc-fortified formula will provide sufficient zinc if the infant is not breastfed. At this stage, zinc-containing foods should be included in the diet, such as beans, nuts, seeds (milled), whole grains, fortified cereals and/or animal foods.
Considerations:
- Zinc supplementation is generally unnecessary for full-term infants who are exclusively breastfed or formula-fed.
- Preterm or low-birth-weight infants may require additional zinc supplementation to support growth and immune development.
- The upper intake level (UL) of 4 mg of zinc per day for infants 0-6 months and 5 mg of zinc per day for infants 7-12 months should be payed attention to, to avoid adverse effects.
Summary: Zinc requirements are usually met through breast milk, zinc-fortified formula and zinc-containing foods at this stage. If supplementation is used, beware to not exceed the given UL for each age group. A common dose for supplementing is 2-3 mg of zinc per day.
Toddlers (1-3 years)
Rationale: Zinc is essential for growth, immune function, and cognitive development in toddlers. Zinc deficiency can lead to growth delays, increased susceptibility to infections, and skin conditions like dermatitis.
Recommendation:
Diet: Ensure a diet rich in zinc-containing foods, such as beans, nuts, seeds (milled), whole grains, fortified cereals and/or animal based food products
Supplementation: If dietary intake is insufficient, consider zinc supplementation. A common supplementation dose for this age group ranges from 2 to 5 mg per day.
Considerations:
- Zinc absorption can be inhibited by high levels of phytates (found in several whole plant based foods, such as grains and legumes). For children who follow a diet high in these products (e.g. a whole-food plant-based diet), a higher intake of zinc containing foods and/or culinary techniques for enhancing zinc bioavailability are encouraged (e.g. soaking, cooking, germination and fermentation of zinc containing foods).
- Zinc deficiency in this age group can impair growth and immune response.
Summary: most children at this stage can meet their zinc requirements through a daily intake of zinc containing foods, especially if enhancing of bioavailability practices are used. In case of insufficient dietary intake or suspicion of deficiency, a supplement can be recommended, with 2-5 mg of zinc per day for this age group.
Children (4-8 years)
Rationale: Zinc supports physical growth, immune function, and cognitive development in this age group. Adequate intake of zinc is particularly important as children grow rapidly and develop new cognitive skills.
Recommendation:
Diet: Ensure a diet rich in zinc-containing foods, such as beans, nuts, seeds (milled), whole grains, fortified cereals and/or animal based food products
Supplementation: If dietary intake is insufficient, consider zinc supplementation. A common supplementation dose for this age group is 10 mg per day.
Considerations:
- Zinc absorption can be inhibited by high levels of phytates (found in several whole plant based foods, such as grains and legumes). For children who follow a diet high in these products (e.g. a whole-food plant-based diet), a higher intake of zinc containing foods and/or culinary techniques for enhancing zinc bioavailability are encouraged (e.g. soaking, cooking, germination and fermentation of zinc containing foods).
- Zinc deficiency in this age group can impair growth and immune response.
Summary: most children at this stage can meet their zinc requirements through a daily intake of zinc containing foods, especially if enhancing of bioavailability practices are used. In case of insufficient dietary intake or suspicion of deficiency, a supplement can be recommended, with approximately 10 mg of zinc per day for this age group.
Children (9-13 years)
Rationale: Zinc is important for maintaining immune function, skin health, and proper growth during the pre-adolescent years. Zinc deficiency during this period can result in impaired immune function and delayed wound healing.
Recommendation:
Diet: Ensure a diet rich in zinc-containing foods, such as beans, nuts, seeds (milled), whole grains, fortified cereals and/or animal based food products
Supplementation: If dietary intake is insufficient, consider zinc supplementation. A common supplementation dose for this age group is 10 mg per day.
Considerations:
- Zinc absorption can be inhibited by high levels of phytates (found in several whole plant based foods, such as grains and legumes). For children who follow a diet high in these products (e.g. a whole-food plant-based diet), a higher intake of zinc containing foods and/or culinary techniques for enhancing zinc bioavailability are encouraged (e.g. soaking, cooking, germination and fermentation of zinc containing foods).
- Zinc deficiency in this age group can impair growth and immune response.
Summary: most children at this stage can meet their zinc requirements through a daily intake of zinc containing foods, especially if enhancing of bioavailability practices are used. In case of insufficient dietary intake or suspicion of deficiency, a supplement can be recommended, with approximately 10 mg of zinc per day for this age group.
Adolescents (14-18 years)
Rationale: Zinc plays a critical role in adolescent growth, immune health, and sexual development. Zinc needs are higher for men.
Recommendation:
Diet: Ensure a diet rich in zinc-containing foods, such as beans, nuts, seeds (milled), whole grains, fortified cereals and/or animal based food products
Supplementation: If dietary intake is insufficient, consider zinc supplementation. A common supplementation dose for this age group is 10 mg per day.
Considerations:
- Zinc absorption can be inhibited by high levels of phytates (found in several whole plant based foods, such as grains and legumes). For adolescents who follow a diet high in these products (e.g. a whole-food plant-based diet), a higher intake of zinc containing foods and/or culinary techniques for enhancing zinc bioavailability are encouraged (e.g. soaking, cooking, germination and fermentation of zinc containing foods).
- Zinc deficiency in this age group can lead to delayed growth, poor immune function, and acne. Inadequate dietary intake may warrant supplementation.
Summary: most adolescents at this stage can meet their zinc requirements through a daily intake of zinc containing foods, especially if enhancing of bioavailability practices are used. In case of insufficient dietary intake or suspicion of deficiency, a supplement can be recommended, with approximately 10 mg of zinc per day for this age group.
Special Populations at Risk for Zinc Deficiency
Certain children are at a higher risk for zinc deficiency and may require supplementation:
- Whole-food plant-based Diets: Children following plant-based diets may have lower zinc absorption due to limited bioavailability in whole plant foods. Culinary techniques that enhance zinc bioavailability such as soaking, cooking, germination and fermentation of zinc containing foods are encouraged, and/or a higher intake of these foods in the diet. A zinc supplement may be recommended if clinical assessment suggests an inadequate intake.
- Malnourished Children: Children in low-income households or those with inadequate access to nutrient-dense foods may have insufficient zinc intake and are at higher risk of deficiency.
- Children with Chronic Illnesses: Conditions that affect nutrient absorption, such as cystic fibrosis, inflammatory bowel disease, or short bowel syndrome, can increase the risk of zinc deficiency. These children may require higher doses of zinc.
- Children with Poor Appetite: Picky eaters or those with eating disorders may have limited dietary variety, leading to inadequate zinc intake.
- Pregnant and Lactating Adolescents: Adolescents who are pregnant or breastfeeding have increased zinc requirements to support fetal development or lactation.
Safety and Monitoring of Zinc Supplementation
Toxicity: While zinc is essential for health, excessive zinc intake can lead to toxicity. Symptoms of zinc toxicity include nausea, vomiting, diarrhea, stomach cramps, and a metallic taste. Long-term overuse can impair immune function, reduce copper absorption, and interfere with iron metabolism. Prevention of toxicity is encouraged through a careful use of supplements in adequate contexts and doses.
Monitoring: Zinc status can be assessed through serum zinc levels, although this is typically only required in children with suspected deficiency. The cut-off concentration is 70 ug/dL, but this is not sufficiently sensitive to diagnose an insufficient intake in apparently normal subjects whose usual dietary intake is close to the average requirements. Children receiving zinc supplements should be monitored for side effects and adverse reactions.
References
- Institute of Medicine (US) Panel on Micronutrients. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, lodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington (DC): National Academies Press (US); 2001. 12, Zinc. Available from: https://www.ncbi.nlm.nih.gov/books/NBK222317/
- International Zinc Nutrition Consultative Group (IZINCG), Brown, K. H., Rivera, J. A., Bhutta, Z., Gibson, R. S., King, J. C., Lönnerdal, B., Ruel, M. T., Sandtröm, B., Wasantwisut, E., & Hotz, C. (2004). International Zinc Nutrition Consultative Group (IZiNCG) technical document #1. Assessment of the risk of zinc deficiency in populations and options for its control. Food and nutrition bulletin, 25(1 Suppl 2), S99–S203.