Vitamin D3 is an allopathic medicine The correct dosage of Vitamin D3 depends on the patient's age, gender, and medical history. This information has been provided in detail in the dosage section. Find out how vitamin D3 can benefit your health, how you can meet your needs and the potential safety concerns and side effects of supplementation. Cholecalciferol is vitamin D3 . Vitamin D helps your body absorb calcium. Vitamin D is also essential for maintaining a healthy immune system. The function of the immune system is to prevent or limit infection. Cholecalciferol is used as a dietary supplement in people who do not get enough vitamin D in their diets to maintain adequate health. Since your diet may not be meeting the daily requirement of vitamin D, therefore you may need 1000 - 3000 IU/day of supplements of vitamin D . Vitamin D3 is a form of vitamin D which is used as a supplement in patients with vitamin D deficiency.