Cholecalciferol, the type of vitamin D3 that is essential for general health and wellbeing, is provided by AMS?? Xtra-D3 10,000 IU. This vitamin is necessary yet scarce in many meals, but it promotes many body functions, including bone health, which lowers the risk of falls and injuriesƒ??especially in older persons. Vitamin D3 also contributes to improved immune system function and muscle performance.