Table 1.
Current estimates of daily dietary zinc requirements (EAR or NR, RDA or RNI) and estimated safe upper levels of zinc intake (UL), in milligrams/day, as proposed by IOM, IZiNCG and FAO/WHO for children and adolescents, and doses of supplemental zinc provided in reviewed studies 1.
| IOM [2] | IZiNCG [1] | EFSA [4] | WHO/FAO [3] | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Age Range | EAR † | RDA * | NOAEL UL ‡ |
EAR † ^mix/unref |
RDA * ^mix/unref |
NOAEL UL ‡ |
Age Range | NOAEL UL ‡‡ |
Age Range | Ref wt 2 kg | NR ^^h/m/L Avail. |
RNI ^^h/m/L Avail. |
LOAEL UL ‡‡ |
| 0–6 m | - | 2 | 4 | - | - | - | - | - | 0–3 m | - | - | 1.1/2.8/6.6 | - |
| 3–6 m | 6 | 0.5/1.2/2.9 | - | ||||||||||
| 6–12 m | - | 1.7/2.8/5.6 | - | ||||||||||
| 7–11 m | 2.5 | 3 | 5 | 3/4 | 4/5 | 6 | - | - | 7–12 m | 9 | - | 2.5/4.1/8.4 | 13 |
| 1–3 y | 2/2 | 3/3 | 8 | 1–3 y | 7 | 1–3 y | 12 | 1.7/2.8/5.5 | 2.4/4.1/8.3 | 23 | |||
| 3–6 y | 3/4 | 4/5 | 14 | 3–6 y | 17 | 1.9/3.2/6.5 | 23 | ||||||
| 4–6 y | 10 | 4–6 y | - | 2.9/4.8/9.6 | |||||||||
| 4–8 y | 4.0 | 8 | 12 | ||||||||||
| 7–10 y | 10 | 6–10 y | 25 | 2.3/3.7/7.5 | 28 | ||||||||
| 7–9 y | 3.3/5.6/11.2 | ||||||||||||
| 9–13 y | 7.0 | 8 | 23 | 5/7 | 6/9 | 26 | 11–14 y | 18 | |||||
| Male/Female | |||||||||||||
| 10–18 y F | 4.3/7.2/14.4 | ||||||||||||
| 10–18 y M | 5.1/8.6/17.1 | ||||||||||||
| 10–12 y F | 47 | 3.2/5.3/10.7 | 32 | ||||||||||
| 10–12 y M | 49 | 3.9/6.5/13.1 | 34 | ||||||||||
| 12–15 y F | 47 | 3.0/5.0/10.1 | 36 | ||||||||||
| 12–15 y M | 49 | 3.7/6.2/12.4 | 40 | ||||||||||
| 14–18 y F | 7.3 | 9 | 34 | 7/9 | 9/11 | 39 | 15–17 y | 22 | 15–18 y F | 47 | 2.6/4.4/8.8 | 38 | |
| 14–18 y M | 8.5 | 11 | 34 | 8/11 | 10/14 | 44 | 15–18 y M | 49 | 3.0/5.0/10.0 | 48 | |||
1 Original to this manuscript using data from references cited. IOM = United States Institute of Medicine, IZiNCG = International Zinc Nutrition Consultative Group, WHO/FAO = the World Health Organization/Food and Agriculture Organization of the United Nations. † EAR = estimated average requirement; similar to NR = normative requirements, as measures of physiological requirement, NRs converted to mg/day using reported reference weights from reference: [3]. * RDA = recommended dietary allowance; similar to RNI = recommended nutrient intake, as estimates of dietary intake required to meet the physiological requirements of most (>97%) individuals, and similar to currently recommended RI = Recommended Intake. ‡ UL estimated based on No Observed Adverse Effects Level. ‡‡ UL estimated based on Lowest Observed Adverse Effects Level in adults. 2 ref wt kg = reference weight in kilograms. ^mix/unref = mixed/unrefined as follows: Mixed: refined vegetarian or mixed diets, such as those with phytate:zinc molar ratios ≤ 18. Unrefined: unrefined cereal-based diets, such as those with phytate:zinc molar ratios > 18. ^^h/m/l avail. = high/medium and low availability as follows: High availability: Refined diets low in cereal fiber, low in phytic acid content, and with phytate–zinc molar ratio < 5; adequate protein content principally from non-vegetable sources, such as meats and fish. Includes semi-synthetic formula diets based on animal protein. Moderate availability: Mixed diets containing animal or fish protein. Lacto-ovo, ovo-vegetarian, or vegan diets not based primarily on unrefined cereal grains or high-extraction-rate flours. Phytate–zinc molar ratio of total diet within the range 5–15, or not exceeding 10 if more than 50% of the energy intake is accounted for by unfermented, unrefined cereal grains and flours and the diet is fortified with inorganic calcium salts (>1 g Ca2+/day). Availability of zinc improves when the diet includes animal protein or milks, or other protein sources or milks. Low availability: Diets high in unrefined, unfermented, and ungerminated cereal grain, especially when fortified with inorganic calcium salts and when intake of animal protein is negligible. Phytate–zinc molar ratio of total diet exceeds 15, high-phytate, soya-protein products constitute the primary protein source. Diets in which, singly or collectively, approximately 50% of the energy intake is accounted for by the following high-phytate foods: high-extraction-rate (≥90%) wheat, rice, maize, grains and flours, oatmeal, and millet; chapatti flours and tanok, and sorghum, cowpeas, pigeon peas, grams, kidney beans, black-eyed beans, and groundnut flours. High intakes of inorganic calcium salts (>1 g Ca2+/day), either as supplements or as adventitious contaminants (e.g., from calcareous geophagia), potentiate the inhibitory effects and low intakes of animal protein exacerbates these effects. m = months, y = years, M = male, F = female.