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Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc
FINDINGS BY LIFE STAGE AND GENDER GROUP
Infants Ages 0 through 12 Months
Method Used to Set the Adequate Intake
No functional criteria of vitamin A status have been demonstrated that reflect response to dietary intake in infants. Thus, recommended intakes of vitamin A are based on an Adequate Intake (AI) that reflects a calculated mean vitamin A intake of infants principally fed human milk.
Ages 0 through 6 Months. Using the method described in Chapter 2, the AI of vitamin A for infants ages 0 though 6 months is based on the average amount of vitamin A in human milk that is consumed. After rounding, an AI of 400 μg retinol activity equivalents (RAE)/day is set based on the average volume of milk intake of 0.78 L/day (see Chapter 2) and an average concentration of vitamin A in human milk of 1.70 μmol/L (485 μg/L) during the first 6 months of lactation (Canfield et al., 1997, 1998) (see Table 4-5). Because the bioconversion of carotenoids in milk and in infants is not known, the contribution of carotenoids in human milk to meeting the vitamin A requirement of infants was not considered.
TABLE 4-5 Vitamin A in Human Milk
Average Maternal Intake
Butte and Calloway, 1981
23 Navajo women
Chappell et al., 1985
Canfield et al., 1997
6 women, 23–36 y
Canfield et al., 1998
5 women, 23–36 y
a Vitamin A intake based on reported data or concentration (μg/L) × 0.78 L/day.