VITAMIN D 25(OH)/VITAMIN D AND VITAMIN D 1, 25OH

What is tested in Vitamin D Test

Vitamin D test checks the level of 25-hydroxy Vitamin D in the body. Vitamin D undergoes a lot of processing in the body and the first transformation of vitamin D occurs in the liver when it is converted to 25 hydroxy vitamin D. 25 hydroxy vitamin D is good indicator of vitamin D in the body and hence it is checked in this test.

Why is Vitamin D Testing Ordered

Vitamin D test or 25-hydroxy vitamin D test is ordered when bone weakness or other bone disorders are suspected. Vitamin D is produced naturally by our body when skin is exposed to sun rays. One would expect that Indians should have plenty of Vitamin D as India has abundant sunshine. However, Indians now lead the world in vitamin D deficiency. This is because people spend little or no time outdoors in the sun especially in urban India.

Vitamin D is required in the body for proper calcium absorption. Lack of vitamin D can lead to body aches and brittle bones. It is also a leading cause of depression.

It is ordered in patient with following conditions-

• Signs or symptoms of osteoporosis or osteomalacia
• Increased alkaline phosphatase with otherwise normal liver function tests
• Hyperparathyroidism, hypo- or hypercalcaemia
• Malabsorption (e.g. cystic fibrosis, inflammatory bowel disease, untreated coeliac disease)
• Deeply pigmented skin, or chronic and severe lack of sun exposure for occupational or residential reasons.
• Medications known to decrease 25OH-D levels (mainly anticonvulsants)
• Chronic renal failure and renal transplant recipients.
• To help monitor the effectiveness of the treatment for Vitamin D deficiency.

INTERPRETATION OF VITAMIN D TEST RESULT

25-OH Vitamin D deficiency provides information about the nutritional intake, sunlight exposure or intestinal absorption of the vitamin.