TABLE 2.
RNIs for infants and lactating women: FAO/WHO1
| Milk | Infant AI | Lactation, units/d | |||||||
|---|---|---|---|---|---|---|---|---|---|
| Nutrient | Concentration, unit/L | Intake from milk (0–6 mo),2 units/d | 0–6 mo | 7–12 mo | Increment over NPNL | EAR | RNI | Data | Comments |
| Thiamin, mg | 0.21 | 0.16 | 0.2 | 0.3 | +0.4 | N/A | 1.5 | Used IOM value for milk (2). Increase for lactation accounts for increased energy cost. | See Table 1 |
| Riboflavin, mg | 0.35 | 0.26 | 0.3 | 0.4 | +0.5 | N/A | 1.6 | Used IOM data for milk and infant (2). Increase for lactation assumes efficiency for milk production = 70%. | See Table 1 |
| Niacin, mg and NE | 1.5 niacin +3.5 mg NE as tryptophan | 1.4 niacin, but total 4 mg NE | 2.0 mg niacin | 4 mg NE | +3 | N/A | 17 | No reference for 1.5 mg/L. Tryptophan value from (1). Increase for lactation supports additional energy expenditure. | — |
| Vitamin B-6, mg | 0.13 | 0.1 | 0.1 | 0.3 | +0.7 | N/A | 2.0 | Used IOM data (2). For age 7–12 mo, extrapolation based on body weight. For lactation, prudent to add 0.6 mg (although 0.7 mg added) to avoid poor status in infant (57). | See Table 1 |
| Vitamin B-12, μg | 0.4 | 0.3 | 0.4 | 0.7 | +0.4 | 2.4 | 2.8 | Used IOM data (2) | See Table 1 [FAO/WHO used the infant intake value (0.32 μg/d) as an EAR] |
| Folate, μg DFE | 85 | 65 | 80 | 80 | +130 (EAR) and +100 (RNI) | 450 | 500 | Used IOM data (2) | See Table 1 |
| Vitamin C, mg | 40 ± 10 | 20 | 25 | 30 | +25 | N/A | 70 | Not clear what study milk value is based on. Assumed 40 mg/L reflects maternal intake and exceeds infant needs. Value for 20 mg/d in milk inconsistent with concentration. Acknowledged that 25 mg/d for infant was arbitrary. In lactation, 20 mg/d in milk and 85% efficiency of absorption. | — |
| Vitamin A, μg RAE | 485 | 375 | 180 (safe intake ≤375) | 190 (safe intake ≤400) | +180 (basal), +350 (safe) | 450 | 850 (safe) | Found wide range of concentrations in reports but source of milk value not cited; no deficiency at 120–170 μg RAE/d so 180 is “mean” level but inadequate to build infant stores. After 6 mo of lactation mother's requirement falls since infant eats solid foods. | Only nutrient where estimate for >6 mo of lactation is reduced due to infant eating other foods |
| Vitamin D, IU | — | — | 200 | 200 | 0 | N/A | 200 | Milk D values not used. | Assumed that in lactation little purpose in recommending additional vitamin D for mother |
| Vitamin E, mg TE | 3.2 ± 1.8 (mean ± SD) | 2.7 | 3 | 3 | 0 | N/A | Insufficient data | Milk concentration from one study (23); n = 24. In lactation, no evidence that requirements differ from NPNL women, and needs met from increased energy intake. | Mature milk (12 d to 5 mo) from milk bank in Sweden, collected after infant fed |
| Vitamin K, μg | 2 | 1.6 | 5 | 10 | 0 | N/A | 55 | No specific source for milk concentration but 1 μg/kg is based on RNI. Need 100 mL colostral milk/d (0.2–0.3 μg vitamin K) during first week for normal hemostasis; 5 μg/d needed to prevent vitamin K deficiency bleeding. | 5 μg/d cannot be met if exclusively breastfed. Milk content is 100 times less than amount in formula |
| Iron, mg | 0.24 (from assumed intake of 0.3) | 0.3 | — | 6.2 | −9.6 | N/A | 10 | Source of milk value not cited. Age 7–12 mo AI assumes 15% bioavailability. In lactation, 0.3 mg in milk + 0.8 mg basal losses. | Milk concentration here calculated from assumed intake of 0.3 mg/d. Requirements in lactation lower due to amenorrhea |
| Copper | — | — | — | — | — | — | — | — | No recommendations |
| Zinc, mg | 2–3 (1 mo), 0.9 (>3 mo) | 1.4 (1–3 mo) | 1.1 | 0.8 | +2.8, +2.3, +1.3 for 0–3, 3–6, 6–12 mo respectively. | N/A | 5.8, 5.3, 4.3 for ages 0–3, 3–6, 6–12 mo, respectively. | Milk value from WHO (55) based on Krebs et al. (58); n = 48. Assumes 80% bioavailability when exclusively breastfed. | United States: age 1–12 mo; no justification provided for high bioavailability assumption |
| Calcium, mg | 360 | ∼280 | 300 | 400 | 0 | N/A | 1000 | Milk data from Nordin (59). For lactation, evidence of no increase in calcium requirements. | Recommended intake assumes 50% absorption provides 120 mg Ca/d needed for normal growth |
| Magnesium, mg | 29 | 20–26 | 26 | 54 | +50 | N/A | 270 | Milk concentration from 2 studies (60, 61). Assumes absorption from milk of 80–90%. | Original references not available. Justification for high bioavailability assumption is that isotope studies show 50–80% absorption from human milk and formulas. |
| Iodine, μg/kg | — | — | 15 | 15 | +1.5 | N/A | 3.5 | No data on milk included. | — |
| Selenium, μg | 18.5 | 6 | 6 | 10 | +9 (0–6 mo), +16 (7–12 mo) | N/A | 35 (0–6 mo), 42 (7–12 mo) | Milk value from WHO-IAEA international survey in developed and developing countries (62); n = >500. Assumes 80% absorption. Wide range of milk concentrations depending on maternal intake. | Six countries, 3 mo of lactation. No justification provided for high bioavailability assumption |
1Data were obtained from the WHO/FAO (63). AI, Adequate Intake; DFE, dietary folate equivalent; EAR, Estimated Average Requirement; IAEA, International Atomic Energy Agency; IOM, Institute of Medicine; N/A, not available/not estimated; NE, niacin equivalent; NPNL, nonpregnant, nonlactating; RAE, retinol activity equivalent; RNI, recommended nutrient intake; TE, tocopherol equivalent.
2Calculation of infant intake assumes 0.75 L milk/d consumed from ages 0–6 mo.