Hypovitaminosis D is common in Asian Indians despite plenty of sunshine and relates to their skin pigmentation and poor sunshine exposure. Serum 25(OH)D levels are <20 ng /ml in up to 90% of them and therefore, based on the modern cut off, majority of apparently healthy normal Asian Indians would be classified as vitamin D deficient. Though, several investigators have highlighted the paradox of hypovitaminosis D in sunny Indian environment, there are only limited studies which have assessed its functional significance. To date, the significance of low serum 25(OH)D in them have been analyzed in terms of its inverse relationship with serum parathyroid hormone levels and variable association with reduced bone mineral content at hip and spine on DXA. Recently we have shown impairment in the absorption of intestinal calcium in 25(OH)D and its reversal after eight weeks of cholecalciferol supplementation. Present study is being taken to further understand the functional significance of 25(OH)D in terms of its effect on Skeletal muscle strength including its energy metabolism, bone mineral homeostasis and Th1/Th2 cytokines expression in Asian Indians with chronic biochemical hypovitaminosis D