Cleveland Clinic, USA notes that 400 International Units (IU) of vitamin D per day is necessary to prevent rickets, but an overwhelming number of physicians and researchers believe this level is too low to help achieve optimal health and reduce the risk of disease. They say the Institute of Medicine (IOM) should consider revising their current vitamin D recommendations, which are below:

– 200 International Units IU per day for adults age 50 and younger
– 400 IU per day for adults aged 51 to 70 years
– 600 IU per day for adults aged 70 years.

It is not clear just how much vitamin D is needed for increased health and disease risk reduction. However, many physicians are now recommending 1,000 IU to 2,000 IU daily for most adults. The physician must decide how much vitamin D is required for an individual.

Caution: Too much vitamin D can cause the body to absorb too much calcium, which can cause kidney stones or damage.