chosen. To cover the needs of all adults ages 51 through 70 years, the above value was doubled for an AI of 10 µg (400 IU).

AI for Men

51 through 70 years

10 µg (400 IU)/day

AI for Women

51 through 70 years

10 µg (400 IU)/day

Ages > 70 Years
Indicator Used to Estimate the AI

Serum 25(OH)D. There is strong evidence for a decrease in circulating concentrations of 25(OH)D and increased risk of skeletal fractures with aging, and it is most apparent after the age of 70 years (Chevalley et al., 1994; Dawson-Hughes et al., 1991; Hordon and Peacock, 1987; Lamberg-Allardt et al., 1989; Lips et al., 1988; McGrath et al., 1993; Ng et al., 1994; Ooms et al., 1995; Villareal et al., 1991; Webb et al., 1990). Villareal et al. (1991) concluded that subclinical vitamin D deficiency with serum 25(OH)D concentrations of less than 37.5 nmol/liter (15 ng/ml) was associated with mild secondary hyperparathyroidism, lower serum calcium and phosphate levels, lower urinary calcium, and higher serum alkaline phosphatase.

Information from descriptive studies in the aging population suggests that both lack of sunlight and low intake of vitamin D influence serum 25(OH)D concentration in elderly subjects. During the winter months (November to May) in Omaha, Nebraska, all but 8 percent of 60 women living in nursing homes (mean age 84 years) and all but 1.6 percent of 64 free-living women (mean age 71 years) maintained serum 25(OH)D levels greater than 30 nmol/liter (12 ng/ml), when daily vitamin D intake was estimated to be 5.2 µg (207 IU) for the nursing home residents and 3.4 µg (135 IU) for the free-living women (Kinyamu et al., 1997). In another study during the winter months (January to May) in New York City with 109 male and female nursing home residents (mean age 82 years), serum 25(OH)D concentration was greater than 37.5 nmol/liter (15 ng/ml) in those taking a vitamin D supplement of 10 µg (400 IU)/day (O'Dowd et al., 1993). In those residents with mean vitamin D intakes of 7.1 µg (283 IU)/day, 14 percent had serum 25(OH)D levels below 25 nmol/liter (10 ng/ml). Similarly, in 116 subjects (mean age 81) who were confined indoors for at least 6 months in Baltimore, serum 25(OH)D concentration was below 25 nmol/liter



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