Inadequate exposure to sunlight or lack of dietary vitamin D results in a deficiency. Mal absorption syndromes like sprue or the presence phytates can cause deficiency. Chronic renal disease can also result in deficiency.

Signs and Symptoms

Deficiency of vitamin D results in the inadequate absorption of calcium and phosphate.
In children the result is a failure to mineralise newly formed bone and cartilage matrix, causing the defect in growth known as rickets. In adults the vitamin D deficiency results in osteomalacia, a disease characterised by generalised accumulation of under mineralised bone matrix. It may be associated with extreme bone pain and tenderness. Muscle weakness is also typical. Gross deformity of the bone occurs only in advanced stages of the disease.

Prevention and treatment

The curative dose of vitamin D for the treatment of fully developed rickets is larger than the prophylactic (large) dose. One thousand units daily will normalise calcium and phosphate concentrations in approximately 10 days. However, a daily dose of 3000 - 4000 units is prescribed for more rapid healing. Certain conditions are known to lead to poor absorption of vitamin D. If untreated by supplementation, a frank deficiency may develop.

Vitamin D
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