D3 2500 provides 2,500 IU (62.5 mcg) of vitamin D3 (cholecalciferol) per capsule for increased bioavailability. The vitamin D receptor is present in nearly all human cells, demonstrating the important role of vitamin D in supporting good health. Despite its importance to many physiological functions, many Canadians have inadequate levels of vitamin D. This may result from insufficient sun exposure, wearing covering clothes, limited consumption of vitamin D-containing foods, dark skin colour, older age, or low intake of vitamin D supplements. With just one capsule daily, this formula helps prevent vitamin D deficiency and may reduce the risk of developing osteoporosis when combined with sufficient calcium, a healthy diet and regular exercise.