Vitamin D status among Kashmiri tribal population: A cross-sectional community-based study

Background & objectives: Vitamin D deficiency (VDD) is prevalent across all age groups in general population of India but studies among tribal populations are scanty. This study aimed to evaluate the prevalence of VDD in the indigenous tribal population of the Kashmir valley and examine associated risk factors. Methods: In this cross-sectional investigation, a total of 1732 apparently healthy tribal participants (n=786 males and n=946 females) were sampled from five districts of Kashmir valley by using probability proportional to size method. Serum 25-hydroxy vitamin D (25(OH)D) levels were classified as per the Endocrine Society (ES) recommendations: deficiency (<20 ng/ml), insufficiency (20-30 ng/ml) and sufficiency (>30 ng/ml). The serum 25(OH)D levels were assessed in relation to various demographic characteristics such as age, sex, education, smoking, sun exposure, body mass index and physical activity. Results: The mean age of the male participants was 43.79 +/- 18.47 yr with a mean body mass index (BMI) of 20.50 +/- 7.53 kg/m2, while the mean age of female participants was 35.47 +/- 14.92 yr with mean BMI of 22.24 +/- 4.73 kg/m2. As per the ES guidelines 1143 of 1732 (66%) subjects had VDD, 254 (14.71%) had insufficient and 334 (19.3%) had sufficient serum 25(OH)D levels. VDD was equally prevalent in male and female participants. Serum 25(OH)D levels correlated positively with serum calcium, phosphorous and negatively with serum alkaline phosphatase. Gender, sun exposure, altitude, physical activity and BMI did not seem to contribute significantly to VDD risk. Interpretation & conclusions: VD deficiency is highly prevalent among Kashmiri tribals, although the magnitude seems to be lower as compared to the general population. These preliminary data are likely to pave way for further studies analyzing the impact of vitamin D supplementation with analysis of functional outcomes.