Vitamin D3 is an essential vitamin that helps to absorb and use Calcium. This is not just important for bone health but general health because without calcium neural communication is significantly impaired. Vitamin D is found in beef, liver, cheese, egg yolks and fish. It is also made in the body when exposed to sunlight. In addition to treating bone conditions, Vitamin D is also used with other medications to treat low levels of calcium caused by parathyroid issues or kidney disease.