winter. These children may need a vitamin D supplement (Oliveri et al., 1993).

AI Summary: Ages 9 through 13 and 14 through 18 Years

Vitamin D that is synthesized in the skin during the summer and fall months can be stored in the fat for use in the winter (Mawer et al., 1972), thereby minimizing the requirement for vitamin D. There is no reason to believe that the increased conversion of 25(OH)D to 1,25(OH)D seen in puberty results in a change in the borderline amount of circulating 25(OH)D that would be considered the minimum for adequacy. Thus, in the absence of additional data, 27.5 nmol/liter (11 ng/ml) is the appropriate cutoff for this age group. Most children aged 8 to 18 years who ingested 2.5 µg (100 IU)/day of vitamin D from margarine had no evidence of vitamin D deficiency and had a normal serum 25(OH)D level (Aksnes and Aarskog, 1982). To cover the needs of all children ages 9 through 18 years, regardless of exposure to sunlight, the above value is doubled for an AI of 5 µg (200 IU)/day.

AI for Boys

9 through 13 years

5.0 µg (200 IU)/day

 

14 through 18 years

5.0 µg (200 IU)/day

AI for Girls

9 through 13 years

5.0 µg (200 IU)/day

 

14 through 18 years

5.0 µg (200 IU)/day

Ages 19 through 30 and 31 through 50 Years
Indicator Used to Estimate the AI

Serum 25 (OH)D. There is little scientific information that relates vitamin D intake, bone health, and vitamin D status as determined by serum 25(OH)D and PTH concentrations in young adult and adult age groups. A descriptive longitudinal study of seven adult female patients in Great Britain (age range 20 to 46 years) who consumed a diet that contained from 0.4 to 1.7 µg (15 to 68 IU)/day of vitamin D revealed that the women developed clinical and biochemical features of osteomalacia after 1 to several years. No information about sunlight exposure was provided, and the patients achieved a positive calcium balance when consuming 2.5 µg (100 IU)/day of vitamin D (Smith and Dent, 1969).

Racial differences were not evident in measures of serum 25(OH)D and PTH in a cross-sectional study in 67 Caucasian (age



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement