Vitamin D deficiency can lead to a loss of bone density, which can contribute to osteoporosis and fractures. Severe vitamin D deficiency can also lead to other diseases. In children, it can cause rickets. Rickets is a rare disease that causes the bones to become soft and bend.
Thus, vitamin D deficiency is usually accompanied by normal blood levels for calcium and phosphorus, high-normal or elevated levels of PTH, normal to elevated levels of total alkaline phosphatase, a low 24-hour urine calcium excretion rate, and low levels of total 25 (OH)D.Cited by: 318.
Vitamin D is heavily involved in the functioning of many bodily systems and low levels can lead to drastic consequences. Since vitamin D is easily obtained from the sun, those who don’t get outside very often and don’t eat fortified foods are liable to develop a deficiency.