Vitamin D, 1, 25-dihydroxy

Measurement of serum 25-OH vitamin D concentrations provide a good index of circulating vitamin D activity in patients not suffering from renal disease. A vitamin D deficiency can lead to bone diseases such as rickets and osteomalacia. Above normal levels can lead to hypercalcemia

Vitamin D is one of the water-soluble vitamins that is required for the healthy formation and maintenance of teeth and bones. Vitamin D can be made in the body when exposed to sunlight, but is also supplemented in the diet. There are two major forms of the vitamin, 1,25 dihydroxyvitamin D and 25 hydroxyvitamin D. 1,25 dihydroxyvitamin D is the active form of the vitamin which is converted by the liver and kidney. A deficiency in vitamin D leads to a bone disorder called rickets and osteomalacia.

Lower than normal vitamin D levels can result from a dietary deficiency, poor absorption of the vitamin or impaired metabolism of the sterol in the liver.

This test is performed in following conditions such as:

• Possibility of kidney disease
• Signs of sarcoidosis or lymphoma
• Bone malformation in children (rickets)
• bone weakness, softness, or fracture in adults (osteomalacia)
• If diagnosed for osteoporosis

Also Known As: Calcitriol; 1,25-Dihydroxycholecalciferol