D3 Cholecalciferol 1000 IU by Bio-Tech is a vitamin that is fat-soluble. This is a supplement that promotes the absorption of calcium and phosphorus in the body. D3 Cholecalciferol 1000 IU by Bio-Tech supports the health of the bones and the joints. It can be taken by those who have disorders of the bones that make them weak. The supplement provides the doses of Vitamin D that the body needs for those who don't get outside in the sun for long periods of time. D3 Cholecalciferol 1000 IU by Bio-Tech is a supplement that increases the amount of calcium in the body.leading to a healthy immune system and skeletal system. It can help in treating some conditions related to the bones. such as rickets and osteoporosis.