iranian diabetics may not be vitamin d deficient more than healthy subjects

there are some reports of decreased serum levels of 25(oh)d in the subjects with impaired glucose tolerance and type 2 diabetes mellitus (t2dm). to assess vitamin d status of the iranian diabetics, a pilot study was conducted on 90 subjects with either type 1 diabetes mellitus (t1dm) (n= 30), t2dm (n= 30), or apparently healthy subjects (n= 30) during fall and winter of 2005. serum samples were analyzed for 25-hydroxycholecalciferol using three different methods: high-performance liquid chromatography (hplc), competitive protein-binding assay (cpba) and radioimmunoassay (ria). in this study serum levels of 25(oh)d were categorized as follows: sufficient ≥ 37 nmol/l; 25 nmol/l ≤ mild deficiency p= 0.024). moreover, both cpba and ria showed some over-estimation of serum 25(oh)d, compared to hplc. our findings suggest that, at least in the cold seasons, vitamin d status of the healthy subjects may not be higher than that of t1dm patients.