ALCITROL--SG Softgels contains Calcitriol, Calcium Citrate, Magnesium Oxide and Zinc Oxide. Calcitriol is a form of vitamin D. Calcitriol administration enhances calcium absorption, reduces serum alkaline phosphatase levels, and may reduce elevated parathyroid hormone levels and the histological manifestations of osteitis fibrosa cystica (a skeletal disorder caused by hyperparathyroidism) and defective mineralization. Calcium is an important mineral for the formation of normal bone tissue. Vitamin-D deficiency can occur at any time of life and may be treated with vitamin D.