The following HTML text is provided to enhance online
readability. Many aspects of typography translate only awkwardly to HTML.
Please use the page image
as the authoritative form to ensure accuracy.
Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc
TABLE S-1 Criteria and Dietary Reference Intake Values for Vitamin A by Life Stage Group
Life Stage Group
Criterion
0 through 6 mo
Average vitamin A intake from human milk
7 through 12 mo
Extrapolation from 0 through 6 mo AI
1 through 3 y
Extrapolation from adult EAR
4 through 8 y
Extrapolation from adult EAR
9 through 13 y
Extrapolation from adult EAR
14 through 18 y
Extrapolation from adult EAR
> 18 y
Adequate liver vitamin A stores
Pregnancy
14 through 18 y
Adolescent female EAR plus estimated daily accumulation by fetus
19 through 50 y
Adult female EAR plus estimated daily accumulation by fetus
Lactation
14 through 18 y
Adolescent female EAR plus average amount of vitamin A secreted in human milk
19 through 50 y
Adult female EAR plus average amount of vitamin A secreted in human milk
aEAR = Estimated Average Requirement. The intake that meets the estimated nutrient needs of half of the individuals in a group.
b RDA = Recommended Dietary Allowance. The intake that meets the nutrient need of almost all (97–98 percent) of individuals in a group.
c AI = Adequate Intake. The observed average or experimentally determined intake by a defined population or subgroup that appears to sustain a defined nutritional status, such as growth rate, normal circulating nutrient values, or other functional indicators of health. The AI is used if sufficient scientific evidence is not available to derive an EAR. For healthy infants receiving human milk, the AI is the mean intake. The AI is not equivalent to an RDA.
be used as a criterion of adequacy. The quality of studies was examined by considering study design; methods used for measuring intake and indicators of adequacy; and biases, interactions, and confounding factors.
Although the reference values are based on data, the data were often scanty or drawn from studies that had limitations in addressing the various questions that confronted the panel. Therefore, many of the questions raised about the requirements for and recommended intakes of these micronutrients cannot be answered fully because of inadequacies in the present database. Apart from studies of overt deficiency diseases, there is a dearth of studies that address specific effects of inadequate intakes on specific indicators of health status, and a research agenda is proposed (see Chapter 15). The
