Vitamin D is a vital vitamin that helps the body absorb calcium and phosphorus. All three together is very important for strengthening the bone. This vitamin is used for the treatment of bone disorders or to treat or prevent bone loss (osteoporosis). Furthermore, vitamin D combined with other medications may be able to treat low levels of phosphate of calcium. The dosage on how much to supplement depends on any current medical conditions, amount of exposure to the sun, age, diet, and response to treatment. It is recommended to supplement it after a meal, but it can be absorbed with or without food. Also, for full absorption, certain medications can decrease the amount of vitamin D, so consulting with a doctor before taking it suggested.