Ages 7 through 12 Months. If the reference body weight ratio method described in Chapter 2 to extrapolate from the AI for thiamin for infants ages 0 through 6 months is used, the AI for thiamin for the older infants would be 0.2 mg/day after rounding. The second method (see Chapter 2), extrapolating from the Estimated Average Requirement (EAR) for adults and adjusting for the expected variance to estimate a recommended intake, gives an AI of 0.3 mg of thiamin, a value higher than that obtained from the first method.

Alternatively, the AI for thiamin for infants ages 7 through 12 months could be calculated by using the estimated thiamin content of 0.6 L of human milk, the average volume consumed by this age group (thiamin content equals 0.13 mg), and adding the amount of thiamin provided by solid foods (0.5 mg), as estimated by Montalto et al. (1985) (see Chapter 2). The result equals approximately 0.6 mg/day. This value was judged to be unreasonably high because it is two to three times the extrapolated values given above. Thus the AI for thiamin is 0.3 mg/day for infants ages 7 through 12 months— the value extrapolated from estimates of adult requirements.

No direct data were found on which to base an EAR for children ages 1 through 8 years. In the absence of additional information, EARs and Recommended Dietary Allowances (RDAs) for these age groups have been extrapolated from adult values by using the method described in Chapter 2.

The RDA for thiamin is set by assuming a coefficient of variation (CV) of 10 percent (see Chapter 1) because information is not available on the standard deviation of the requirement for thiamin; the