. "2 The B Vitamins and Choline: Overview and Methods." Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline. Washington, DC: The National Academies Press, 1998.
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DRI Dietary Reference Intakes: For Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline
weighing 70 kg would require—a higher percentage than that represented by actual weight.
The EAR for adults is an estimate of maintenance needs.
The percentage of extra B vitamins and choline needed for growth is comparable with the percentage of extra protein needed for growth.
On average, total needs do not differ substantially for males and females until age 14, when reference weights differ.
The formula for the extrapolation is
EARchild = EARadult (F),
where F = (Weightchild/Weightadult)0.75 (1 + growth factor). Reference weights from Table 1-2 are used. If the EAR differs for men and women, the reference weight used for adults differs by gender; otherwise, the average for men and women is used unless the value for women is derived from data on men. The approximate proportional increase in protein requirements for growth (FAO/WHO/ UNA, 1985) is used as an estimate of the growth factor as shown in Table 2-1. If only an AI has been set for adults, it is substituted for the EAR in the above formula and an AI is calculated; no RDA will be set.
Setting the RDA
To account for variability in requirements because of growth rates and other factors, a 10 percent coefficient of variation (CV) for the
TABLE 2-1 Growth Factors Used to Extrapolate DRIs
Age Group
Growth Factor
7 mo–3 y
0.30
4–8 y
0.15
9–13 y
0.15
14–18 y, Males
0.15
14–18 y, Females
0.00
NOTE: Growth beyond age 13 for females is assumed to represent a negligible increased requirement for vitamins.
SOURCE: The proportional increase in protein requirements for growth from FAO/ WHO/UNA (1985) was used to estimate the growth factor indicated.
