Longnecker M P, Stram D O, Taylor P R, Levander O A, Howe M, Veillon C, McAdam P A, Patterson K Y, Holden J M, Morris J S, Swanson C A, Willett W C
Department of Epidemiology, UCLA School of Public Health, USA.
Epidemiology. 1996 Jul;7(4):384-90. doi: 10.1097/00001648-199607000-00008.
We examined the validity of using the selenium level in a single biological specimen as a surrogate measure of usual intake. We used data from 77 free-living adults from South Dakota and Wyoming. Subjects provided multiple 1-day duplicate-plate food composites, repeated specimens of blood and toenails, and 24-hour urine collections. We developed a statistical calibration method that incorporated measurement error correction to analyze the data. The Pearson correlation coefficients between selenium intake and a single selenium status measure, after deattenuation to adjust for the effect of within-person variation in intake, were: 0.78 for whole blood, 0.74 for serum, 0.67 for toenails, and 0.86 for urine. We present formulas to estimate the intake of individuals, based on selenium levels in a single specimen of blood, toenails, or urine. In these data, the concentration of selenium in a single specimen of whole blood, serum, or toenails served reasonably well as a measure for ranking subjects according to long-term selenium intake but provided only a rough estimate of intake for each subject.
