Pure & Essential Daily Vitamin D3 provides the most biologically active form of vitamin D that is easily absorbed by the body and taken up into the bloodstream. Small tablets deliver 2000 IU of vitamin D3, suitable for everyday use throughout the year. Excessive doses of vitamin D3 can upset the delicate ratio of calcium and vitamin D in the body, so higher doses should only be taken for acute periods as needed.As vitamin D3 is synthesised in the skin via exposure to sunlight, our production capacity is impaired when sun exposure is limited. Supplementation is therefore considered to be the most effective way to optimise consistently healthy blood levels throughout the year. Vitamin D3, also known as cholecalciferol, is the most biologically active form of vitamin D, as it is readily absorbed and easily utilised by the body.