had not yet been compiled. After the completion of the study, information on total intake was published (Garriguet, 2010).
Considerations about the adequacy of vitamin D intake must be interpreted in view of the fact that these reference values assume that no vitamin D is contributed to the human body by sun exposure. Given the unknowns concerning the contribution from sunlight as well as the inability to recommend an acceptable level of sun exposure, this assumption was necessary. However, it confounds interpretation of the intake assessment. If persons are obtaining some vitamin D from sun exposure, they are less likely to be at risk for inadequacy if their intakes are below the reference value. Although the extent to which this may be the case cannot be determined, a concomitant examination of serum 25OHD levels can assist in better describing the assessment. Moreover, as mentioned earlier, it is an appropriate component of the assessment of dietary adequacy (foods and supplements) because, whenever possible, the assessment should consider biological parameters (IOM, 2000).
Figure 7-4 shows U.S. vitamin D intake from foods alone. Median vitamin D intake levels for males ranged from 272 to 396 International Units (IU)/day depending upon life stage group. For females, median vitamin D intakes spanned between 160 and 260 IU/day. When intake from supplements is considered to provide total intakes (Figure 7-5), all life stage groups for both male and female Americans show a slight increase in values. The most marked increase is among older women, as was the case for calcium. For women 51 to 70 years of age, median intake of vitamin D from both food and supplements increases to 308 IU/day, compared with vitamin D intake from foods alone, at 140 IU/day. For women more than 70 years of age, the increase in median intake associated with supplement use is an additional 196 IU/day (356 IU with supplements vs. 160 IUs from foods alone).
As shown in Figure 7-5, the 95th percentiles for total vitamin D (foods plus supplements) for males and females range between 568 and 940 IU/day, with both this high and low value found among the female life stage