COMPETITIVE PROTEIN?BINDING ASSAY?BASED ENZYME?IMMUNOASSAY METHOD, COMPARED TO HIGH?PRESSURE LIQUID CHROMATOGRAPHY, HAS A VERY LOWER DIAGNOSTIC VALUE TO DETECT VITAMIN D DEFICIENCY IN 9-12 YEARS CHILDREN

摘要

Background: The most reliable indicator of Vitamin D status is circulating concentration of 25 ? hydroxycalciferol (25 (OH) D) routinely determined by enzyme ? immunoassays (EIA) methods. This study was performed to compare commonly used competitive protein ? binding assays (CPBA) ? based EIA with the gold standard, high ? pressure liquid chromatography (HPLC).Methods: Concentrations of 25 (OH) D in sera from 257 randomly selected school children aged 9-11 years were determined by two methods of CPBA and HPLC.Results: Mean 25 (OH) D concentration was 22 ± 18.8 and 21.9±15.6 nmol/L by CPBA and HPLC, respectively. However, mean 25 (OH) D concentrations of the two methods became different after excluding undetectable samples (25.1±18.9 vs. 29±14.5 nmol/L, respectively; P=0.04). Based on predefined Vitamin D deficiency as 25 (OH) DConclusions: Though CPBA may be used as a screening tool, more reliable methods are needed for diagnostic purposes.