The discriminative value of various biochemical parameters in detecting varying degrees of vitamin D deficiency in the Iranian population

Abstract

Background: The present study was designed to assess the status and the discriminatory ability of serum Alk-Ph, Ca, P, and PTH in detecting hypovitaminosis D in some selected Iranian populations. Methods: Using a random cluster sample of apparently healthy men and women, this multi-centric cross-sectional study was carried out among the Iranian urban population of five large cities (Tehran, Tabriz, Mashhad, Shiraz, and Booshehr). Serum levels of 25(OH)D, PTH, Alk-Ph, Ca, and P levels were analyzed. Analysis of variance (ANOVA) was used to estimate the main effects by comparing the mean values of serum PTH, Alk-Ph, Ca, and P at different 25(OH)D levels. The discriminative value of the studied biochemical markers in detecting hypovitaminosis D was assessed by ROC curve analysis. Results: From among the studied subjects, 2164 (57.5 %) had moderate to severe vitamin D deficiency. The areas under the ROC curves showed the low accuracy of PTH (0.579), Alk-Ph (0.478), Ca (0.496), and P (0.406) in detecting subjects with a vitamin D concentration <20 ng / mL. Conclusions: Abnormalities in routine markers of bone profile such as PTH, Alk-Ph, Ca, and P are not adequate enough to discriminate patients with hypovitaminosis D. (Clin. Lab. 2011;57:163-170