Materials and Methods: This cross-sectional population-based survey was conducted among the patients who referred to five laboratories of Ilam from July 2014 to July 2015. The samples were selected by a random procedure. 25-hydroxyvitamin D [25OHD] levels were determined by enzyme-linked immunosorbent assay (ELISA) method. Cut-off points for serum levels of 25OHD were defined as normal (>30 ng/mL), vitamin D insufficiency (VDI) (10-30 ng/mL) and VDD (<10 ng/mL). Data were analyzed using SPSS version 17.0 by descriptive and analytical statistics (chi-square test).

Results: In total, 7725 subjects (5273 females and 2452 males) with a mean age of 34.96±18.10 years were investigated. The prevalence of VDD/VDI combined was estimated to be 65.8%. Its prevalence was 67.3% among females, and 62.8% among the males. The prevalence of VDD and VDI was 12.1% and 53.7%, respectively. The highest prevalence of VDD combined with VDI was estimated for ages between 18 and 60 years (68.3%). The mean 25OHD concentration was 27.02±18.04 ng/mL and this concentration for male and female was 28.39±16.48 and 26.41±18.60, respectively. The relationship between VDD and age and sex was statistically significant (P < 0.001).

Conclusions: The results suggested that VDD and VDI are very prevalent in this region. Accordingly, it is necessary to take certain intervention measures such as medication and vitamin D-enriched nutrition to decrease VDD and VDI.