Vitamin D3 (also known as cholecalciferol) is a fat soluble vitamin, produced within the body when the skin is exposed to uv radiation from sunlight.

People living in northern latitude countries such as the UK are at risk of vitamin D deficiency, particularly during the winter months. Darker skinned ethnic minorities and the elderly are especially at risk.

Vitamin D3 increases the absorption of calcium from the digestive tract, and reduces the excretion of calcium, thereby helping to regulate blood calcium levels. These effects ensure that calcium levels are maintained and allow adequate levels to be stored in bones and teeth.

In addition to maintaining healthy bones and teeth, vitamin D3 also contributes to the normal functioning of the muscles and immune system.