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DRI Dietary Reference Intakes Calcium Vitamin D
sons in both countries above or below designated levels of serum 25OHD. These data are included as information for the users of this report and have been provided by the U.S. Centers for Disease Control and Prevention and by Statistics Canada. However, these data were not reviewed by the committee given that the analyses did not take place until after the close of the committee deliberations.
The intake assessment conducted in this report suggests that calcium remains a nutrient of public health concern in some population groups. Girls 9 to 18 years of age, who have a fairly high requirement for calcium, are clearly falling below desirable intake estimates in both countries when only food sources of calcium are considered, as are women over the age of 50 years. On the other hand, available data from the United States on the total intake of calcium when dietary supplements are considered, suggests that older women on average, at least in the United States, have added to their calcium intakes through supplement use. For girls, the increase in intake that might be attributable to supplement use is small. No life stage groups exceeded the UL for calcium when foods alone were considered. However, when supplement use was taken into account (United States only), those women consuming at the 95th percentile of calcium intake appeared to be at risk for exceeding the UL. This suggests that there may be value in underscoring the need for older girls to modestly increase intake of calcium, and in emphasizing that for older women high intakes from supplements may be concerning.
Due to the desirability of considering biological parameters for intake assessments whenever possible (IOM, 2000), the vitamin D assessment presented some challenges. Although median vitamin D intakes from foods in both countries for all life stage groups were below the EAR of 400 IU/day, these data and any future intake analyses conducted using the IOM methodology (IOM, 2000) should be considered in light of the corresponding serum 25OHD concentrations. However, specific prevalence estimates based on serum values are not provided here because the appropriate application of the IOM methodology outlined in 2000 (IOM, 2000), which is focused on use of dietary intake estimates, is currently unclear and may not be appropriate for use with serum values.
Average serum 25OHD concentrations from the NHANES were well above the 40 nmol/L established as consistent with an intake equivalent to the EAR, although a number of North Americans have serum values below 40 nmol/L. All average values were above 50 nmol/L, the level consistent with an intake equivalent to the RDA. When the U.S. data were “adjusted” to simulate conditions more consistent with winter months, at