This formula packs 10,000 IUs of Vitamin D. Vitamin D is known as essential when it comes to building strong teeth and bones.** Vitamin D3 is a more potent and bioavailable form compared to D2. Assists the body with calcium absorption.** Bolsters the immune system.** In the days immediately after hard training, muscle strength can temporarily decrease as your body recovers, which may impact performance. and,Vitamin D can help improve recovery of muscle strength so you can get back to training hard.** Assists the body with calcium absorption.** . ** These statements have not been evaluated by the Food and Drug Administration. These products are not intended to diagnose, treat, cure or prevent any disease.