Jarrow Formulas Vitamin D3 provides cholecalciferol, which is the form produced by the (human) skin in response to UVB exposure (sunlight), and may also improve vitamin D status better than equivalent amounts of ergocalciferol Jarrow Formulas Vitamin D3 is converted to calcitriol in the body, which enhances dietary calcium and phosphorous absorption, supports the production of osteocalcin (an important structural protein in bone), and supports a healthy immune response. Jarrow Formulas Vitamin D3 Softgels deliver 1000 IU of vitamin D. Take 1 softgel per day, or every other day, with a fat-containing meal, or as directed by your qualified healthcare professional. The goal of Jarrow Formulas is to promote optimal health with high-quality, effective, affordable, and superior formulation of dietary supplements Our customers can be assured of purity, value, and potency. , , Jarrow Formulas Vitamin D3 provides cholecalciferol, which is more biologically active than ergocalciferol (D2). Vitamin D3 is ultimately converted to its hormonally-active form, calcitriol, in the kidney. Calcitriol enhances dietary calcium and phosphorous absorption stimulates the synthesis of osteocalcin (an important structural protein in bone) and supports a healthy immune response. Jarrow Formulas Vitamin D3 provides cholecalciferol, which is the form produced by the (human) skin in response to UVB exposure (sunlight) and may also improve vitamin D status better than equivalent amounts of ergocalciferol (D2). Vitamin D3 is ultimately converted to its hormonally-active form, calcitriol, in the body as needed. Calcitriol enhances dietary calcium and phosphorous absorption supports the production of osteocalcin (an important structural protein in bone) and supports a healthy immune response.