• Supports healthy serum calcium levels* • Promotes calcium absorption* • Supports colon health* Vitamin D3 is a fat-soluble vitamin that helps maintain strong bones and teeth by supporting healthy serum calcium levels. It does this by promoting absorption of calcium in the digestive tract, as well as reducing calcium loss through urine. Additionally, Vitamin D supports colon health, and may promote a healthy immune system. Vitamin D occurs naturally in very few foods, and although it can be produced in the body, obtaining adequate skin absorption from sun exposure can be difficult year round. Vital Nutrients offers supplemental Vitamin D in the active form D3 (also known as cholecalciferol).