Vitamin D3 ( Vitamin D-3 ) 400 IU 100 softgels, Jarrow Formulas

Vitamin D3 Bone Metabolism and Healthy Cell Growth Vitamin D 3 Cholecalciferol Jarrow Formulas Vitamin D3 (cholecalciferol) is from purified fish liver oil and is free of Vitamin A. Fat-soluble Vitamin D 3 is converted by the kidneys into the hormone calcitriol, the activated form of Vitamin D3 which affects a variety of target tissues including bone, intestine, muscle, brain, skin and immune systems cells. Calcitriol enhances calcium and phosphorous absorption and stimulates the synthesis of osteocalcin, an important structural protein in bone. Also, calcitriol is involved in proper cell differentiation (changing of cell function).