Nutrivital Vitamin D3 Fast Absorb tablets contain calcifediol, a form of vitamin D3, which is absorbed faster than colecalciferol when taken orally. Vitamin D maintains bone health and strength and healthy immune system function when dietary intake is inadequate. Maintains vitamin D3 levels in the body when sun exposure is inadequate. Vitamin D helps calcium absorption and a diet deficient in calcium can lead to osteoporosis in later life. Calcifediol is up to 3 times more potent than colecalciferol