Vitamin D 25 Hydroxy

25-hydroxy vitamin D test is used to measure the levels of vitamin D in the blood. 25-hydroxy vitamin D is also called as calcidiol.

What is Vitamin-D?

Vitamin D is an essential compound required for proper growth and development of teeth and bones. There are two forms of vitamin D that can be measured in blood. They are 25-hydroxyvitamin D and 1, 25- dihydroxyvitamin D.

The two sources of vitamin D is endogenous or exogenous. Endogenous sources are produced in the skin by the exposure to sunlight. The exogenous sources are through food and supplements. Vitamin D2 and vitamin D3 are the two chemical structures of the Vitamin D. Vitamin D2 is called ergocalciferol which is mostly found in fortified foods and most vitamin preparations and supplements. Vitamin D3 is called cholecalciferol and is produced in the body and also used in some supplements. These two vitamin D2 and vitamin D3 are converted to 1, 25-dihydroxyvitamin D.

Importance of Vitamin-D:

The main role of vitamin D is to regulate the levels of phosphorus, calcium, and magnesium in the body. Vitamin D helps in the growth of bones. Vitamin D deficiency makes the bones soft, malformed, and unable to repair that is leading to diseases like rickets in children and osteomalacia in adults. It also helps in regulating the immune system and also in the growth of many other tissues. The main sources of vitamin D are fishes like salmon, mackerel, cod liver oil, fortified milk, bread, eggs, and cereals.

Why this test is performed?

This test may be recommended to you if you have any abnormal calcium or phosphorus level or abnormal parathyroid levels. This test is also recommended if you have evidence of bone weakness or bone disorders or if you are at high risk of vitamin D deficiency. This test is also performed before starting the treatment for osteoporosis and later to check the progress of the treatment. This test is recommended to you, if you have a malformation of bones, weakness, osteomalacia, fracture, gastric bypass surgery, malabsorption of fat, people with darker skin, breastfeeding mothers, kidney diseases or sarcoidosis, or lymphomas, etc. This test is also recommended to you if you have a chronic illness such as asthma, psoriasis, or certain immune disorders.

Precautions:

Some anti-seizure drugs such as phenytoin may interact with the test results. An overdose of vitamin tablets also interferes with the test results. Hence, inform your doctor or technician about all your current medications and medical conditions prior to the test.

If your test results show low levels of 25-hydroxyvitamin D, it may indicate a vitamin deficiency. This may be due to low absorption of vitamin D from intestines or low dietary intake of vitamin D in foods or due to less exposure to the sun. If your test results show high levels of 25-hydroxyvitamin D, it may indicate excess dietary intake of vitamin D through nutritional supplements or vitamin tablets.

If you receive abnormal test results, consult your health care provider immediately. Your health care provider may recommend you further tests, treatments, or lifestyle modifications based on your test results.