Cover Image


View/Hide Left Panel

TABLE 2-1 Estimated Growth Factor, by Age Group

Age Group

Growth Factor

7 mo–3 y


4–8 y


9–13 y


14–18 y







SOURCE: Proportional increase in protein requirements for growth from FAO/WHO/ UNA (1985) used to estimate the growth factor.

Setting the Tolerable Upper Intake Level for Children

When data are not available to set the Tolerable Upper Intake Level (UL) for children, the UL for adults is extrapolated down using the reference body weights in Table 1-1:

ULchild = ULadult × Weightadult/Weightchild.

Method for Extrapolating Data from Young to Older Infants

Using the metabolic weight ratio method to extrapolate data from young to older infants involves metabolic scaling but does not include an adjustment for growth because it is based on a value for a growing infant. To extrapolate from the AI for infants ages 0 through 6 months to an AI for infants ages 7 through 12 months, the following formula is used:

AI712 mo = AI0–6 mo × F,

where F = (Weight712mo/Weight06 mo)0.75.

Methods for Determining Increased Needs for Pregnancy

It is known that the placenta actively transports certain nutrients from the mother to the fetus against a concentration gradient (Hytten and Leitch, 1971). However, for many nutrients, experimental data that could be used to set an EAR and RDA or an AI for pregnancy are lacking. In these cases, the potential increased need for these nutrients during pregnancy is based on theoretical consid-

The National Academies of Sciences, Engineering, and Medicine
500 Fifth St. N.W. | Washington, D.C. 20001

Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement