We performed a study to compare the efficacy of Vitamin D3 oral solution with a conventional tablets and capsules in hypovitaminosis D patients. One hundred eighty subjects were divided into three different groups and received vitamin D3 60000 IU per week for eight weeks either in the form of an oral solution or a tablet or a capsule. A significant increase in serum 25(OH)D was observed in vitamin D3 oral solution from baseline (P=0.0001) as compared to a tablet (P=0.0001) and capsule (P=0.0001). A significant decrease in iPTH levels was seen in the vitamin D3 oral solution group from baseline (P=0.0001) and also as compared to a tablet (P=0.0001) and capsule (P=0.0001). Oral solution of vitamin D3 is a nanotechnology-based formulation which was found to be effective and safe. Thus, treatment with vitamin D3 oral solution in hypovitaminosis D patients may result in faster and higher improvement in the normalization of vitamin D levels.