Doctor's Best Vitamin D3 helps maintain immune and bone health and maintain good blood circulation. It helps regulate the levels of calcium and phosphorus necessary for healthy bones and teeth. Helps maintain immune and blood circulation health, approximately 75% of Americans are vitamin D deficient. Doctor's Best Vitamin D3 provides D3 (as cholecalciferol) that the body needs to regulate phosphorus and calcium levels to support bones, teeth, and pump blood through the body. Vitamin D3 is produced in the skin by absorbing the sun's ultraviolet rays and is obtained from food in limited quantities. Sun protection and climatic factors can influence low levels of vitamin D3. Vitamin D3 is beneficial for the immune system, improving blood circulation, bone structure and density, and cell function. It plays a role in most organs and systems of the body and influences the chemical messengers of the immune system. It is recommended to take 1 softgel daily, with or without food, or as recommended by a nutritionally-informed physician Consult your healthcare provider before use if you are taking any prescription medications or if you have a medical condition. Store in a cool dry place.