Vitamin D functions as a hormone with widespread effects on the body. It is important for optimal bone, cardiovascular, neuromuscular, and immune health. Vitamin D3 (cholecalciferol) is more potent than vitamin D2 for raising and maintaining vitamin D blood levels. Adequate calcium and vitamin D throughout life, as part of a well-balanced diet, may reduce the risk of osteoporosis. 50,000 IU of a dry, water-soluble (taste-free, odor-free, hypoallergenic) natural vitamin D3 preparation.