SOURCE: One-day unadjusted intake data from the 1994 CSFII, providedby USDA/ARS Food Survey Research Group, 1996. The data have beenadjusted using the method developed by Nusser et al. (1996).
Table 9-1 illustrates the importance of adjusting distributions before calculating intake percentiles for groups. The means and seven percentiles of intakes of phosphorus from the 1994 CSFII are shown for teenage boys and for young women, with and without adjustment for usual intake using the Nusser et al. procedure (1996). If unadjusted 1-day intake data are used to estimate the prevalence of inadequate phosphorus intakes for young women, the actual prevalence of usual intakes below an EAR of 580 mg (18.7 mmol)/day will be overestimated. As shown in Table 9-1, between 10 and 25 percent of 1-day intakes fall below 580 mg (18.7 mmol)/day, while less than 5 percent of the adjusted intakes are below the EAR. For teenage boys, less than 10 percent would have inadequate intakes using the adjusted distribution and an EAR of 1,055 mg (34 mmol)/day, while almost 25 percent would have inadequate intakes if only the unadjusted distribution were examined.
The adjustment procedure is also crucial when examining the percentage of the population that is above the UL. Using an unadjusted distribution for adolescent boys, 5 percent of the population would have phosphorus intakes above 3,350 mg (108.1 mmol)/day, a level that is approaching the UL of 4,000 mg (129 mmol)/day. This might be considered unacceptably high unless the adjusted