Recommended Daily Zinc Intake
For adults, the recommended daily zinc intake is 8 mg/day for women and 11 mg/day for men, with adjustments needed during pregnancy (12.7 mg/day) and lactation (an additional 2.9 mg/day above baseline requirements). 1
Adults (General Population)
The zinc requirements for adults vary based on sex and dietary phytate content, which significantly affects zinc absorption:
Standard Recommendations
European Guidelines (EFSA) - Phytate-Adjusted
The European Food Safety Authority provides more nuanced recommendations accounting for dietary phytate intake 1:
- Women: 7.5–12.7 mg/day depending on phytate intake 1
- Men: 7.5–16.3 mg/day depending on phytate intake 1
For adults consuming diets with varying phytate levels, recommendations range from 7 mg/day to 16 mg/day 2. Phytate, found in whole grains, legumes, and nuts, inhibits zinc absorption, necessitating higher intake when dietary phytate is elevated 2.
Pregnancy
Pregnant women require 12.7 mg/day of zinc to support fetal development and tissue growth 1. This represents an increase from baseline adult female requirements to account for zinc deposition in fetal tissues and increased maternal metabolic demands.
Lactation
Lactating women need an additional 2.9 mg/day above their baseline requirement (total approximately 10.4–15.6 mg/day depending on body weight and phytate intake) 1. This accounts for zinc losses through breast milk, which typically contains 4-6 mg/L of biotin and requires adequate zinc transfer to the infant 1.
Older Adults
For older adults living independently, zinc requirements align with general adult recommendations 1:
- Women: 12.7 mg/day (EFSA population reference intake) 1
- Men: 16.3 mg/day (EFSA population reference intake) 1
Zinc deficiency is particularly common in older adults, especially those in residential care, due to factors including poor diet, inadequate chewing, impaired gut absorption, and low socioeconomic status 1. Supplementation with 15 mg/day may be necessary if high-protein foods are not regularly consumed 1.
Infants and Children
Infants (0-12 months)
Children (>12 months)
- Children >12 months to 6 years: 50 μg/kg/day, maximum 5 mg/day 3, 5
- School-age children (e.g., 7 years, ~20-25 kg): Approximately 1-1.25 mg/day, not exceeding 5 mg/day 5
Dietary Sources and Absorption Considerations
High-protein foods provide the most bioavailable zinc, including dark meats (tuna, red meat, dark poultry), cheese, eggs, and nuts 1. Zinc should ideally be consumed between meals rather than with food for optimal absorption 3, 5. Avoid consuming zinc with foods high in phytates (whole grains, legumes), which significantly reduce absorption 3, 5.
Upper Limits and Safety
The tolerable upper intake level (UL) is 40 mg/day according to the FDA and 25 mg/day per EFSA 6. Exceeding these limits can cause adverse effects including anemia, neutropenia, and zinc-induced copper deficiency 6. The proximity between the RDA and the safe upper limit is relatively narrow, requiring careful attention to total zinc intake from all sources 7.
Special Clinical Situations
Documented Zinc Deficiency
For confirmed deficiency, therapeutic doses of 0.5-1 mg/kg per day of elemental zinc for 3-4 months are recommended 3, 4, 5.
Acute Diarrhea (Children)
This applies specifically to populations with high zinc deficiency prevalence or signs of malnutrition 4.
High Gastrointestinal Losses
Children with ileostomy, severe diarrhea, or extensive stool output may require higher supplementation, potentially up to 12 mg/day intravenously in severe cases 3.
Monitoring Recommendations
For individuals on long-term zinc supplementation, monitor serum zinc levels and alkaline phosphatase periodically 3, 5. Plasma zinc should be measured concurrently with C-reactive protein (CRP) and albumin for accurate interpretation 3. Watch for signs of secondary copper deficiency, as high zinc intake competitively inhibits copper absorption 5.