No Ordinary Vitamin D3 Supplement Pure D3 5000IU contains a superior form of Vitamin D3 called Cholecalciferol. This form has been clinically proven to be highly absorbable and is the same type produced naturally when your skin is exposed to the sun. It has been found that Cholecalciferol has even high absorption than Ergocalciferol, the plant-based form of Vitamin D. Ensuring your body can reap the benefits from this little drop of sunshine! Playing A Critical Role Vitamin D3 is often overlooked but is key for many functions within the body, in particular maintaining bone & muscle strength, disease prevention, heart health and cell function and growth. Pure D3 5000IU has been specificially designed to restore serum d levels naturally. With higher potency and optimal absorption rapid results naturally occur.