25-hydroxy vitamin D test The 25-hydroxy vitamin D test is the most accurate way to measure how much vitamin D is in your body.Vitamin D helps control calcium and phosphate levels in the body.A blood sample is needed. Usually, you will not need to fast. But, this depends on the laboratory and the testing method used. So, follow any instructions for not eating before the test.When the needle is inserted to draw blood, some people feel moderate pain. Others feel only a prick or stinging. Afterward, there may be some throbbing.This test is done to determine if you have too much or too little vitamin D in your blood.The normal range of vitamin D is measured as nanograms per milliliter (ng/mL). Many experts recommend a level between 20 and 40 ng/mL. Others recommend a level between 30 and 50 ng/mL.The examples above are common measurements for results of these tests. Normal value ranges may vary slightly among different laboratories. Some laboratories use different measurements or test different samples.
Talk to your doctor about the meaning of your specific test results, and whether you may need vitamin D supplements.A lower-than-normal level can be due to a vitamin D deficiency, which can result from:Lack of exposure to sunlightLack of enough vitamin D in the dietLiver and kidney diseasesPoor food absorptionUse of certain medicines, including phenytoin, phenobarbital, and rifampin A low vitamin D level is more common in African-American children (especially in the winter), as well as in infants who are breastfed only. A low vitamin D level may be associated with an increased risk of developing cancer.A higher-than-normal level may be due to excess vitamin D, a condition called hypervitaminosis D. This is most commonly caused by taking too much vitamin D. It can result in too much calcium in the body (hypercalcemia). This leads to many symptoms and kidney damage.Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.
Other risks associated with having blood drawn are slight but may include:Excessive bleedingFainting or feeling light-headedHematoma (blood accumulating under the skin)Infection (a slight risk any time the skin is broken)25-OH vitamin D test; Bouillon R. Vitamin D: from photosynthesis, metabolism, and action to clinical applications. In: Jameson JL, De Groot LJ, de Kretser DM, et al, eds. Endocrinology: Adult and Pediatric. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 59.Chernecky CC, Berger BJ. Vitamin D (Cholecalciferol) – plasma or serum. In: Chernecky CC, Berger BJ, eds. Laboratory Tests and Diagnostic Procedures. 6th ed. Philadelphia, PA: Elsevier Saunders; US Preventive Services Task Force. Screening for vitamin D deficiency in adults: US Preventive Services Task Force recommendation statement. Ann Intern Med. 2015;162(2):133-140. Vitamin D helps the body maintain strong bones. The 25-hydroxy vitamin D test is used to detect bone weakness or other bone malfunctions or disorders that occur as a result of a vitamin D deficiency.
The results of a 25-hydroxy vitamin D test can help your doctor recommend an appropriate treatment to make sure your body is getting enough vitamin D. Vitamin D helps your body absorb calcium and maintain strong bones throughout your entire life. Your body produces vitamin D when the sun’s UV rays contact your skin. Other good sources of the vitamin include fish, eggs, and fortified dairy products. It’s also available as a dietary Vitamin D must go through several processes in your body before your body can use it. The first transformation occurs in the liver. body converts vitamin D to a chemical known as 25-hydroxyvitamin D, also called The 25-hydroxy vitamin D test is the best way to monitor vitaminThe amount of 25-hydroxyvitamin D in your blood is a good indication of how much vitamin D your body has. The test can determine if your vitamin D levels are too high or too low. The test is also known as the 25-OH vitamin D test and the
It can be an important indicator weakness) and rickets (bone Your doctor may request a 25-hydroxy vitamin D test for severalIt can help them figure out whether too much or too little vitamin D is causing bone weakness or other abnormalities. It can also monitor people who are at risk for having a vitamin D deficiency. Those who are at high risk of having low levels of vitamin D people who don’t get much exposure to the sunolder adultspeople with obesitybabies who are breastfed only (formula is usually fortified with vitamin D)people who have had gastric bypass surgerypeople who have a disease that affects the intestines, such as Crohn’s disease. (This condition makes it difficult for your body to absorb nutrients.) Your doctor may also want you to do a 25-hydroxy vitamin D test if they’ve already diagnosed you with a vitamin D deficiency and they want to check if treatment is working. Your doctor will tell you not to eat anything for four to eight
hours before the test. The 25-hydroxy vitamin D test requires a common blood test. doctor or a lab technician will draw blood from a vein in your arm using aA quick finger prick will more than likely provide enough for a blood sample in children and infants. No specific number range indicates vitamin D deficiency. depend on your age, gender, and the testing methods used. Results can also slightly vary from lab to lab. Low blood levels of 25-hydroxy vitamin D usually mean one (or more) of the following: you aren’t eating a balanced, complete dietyour intestines aren’t absorbing the vitamin properlyyou’re not spending enough time outside to absorb adequate vitamin D levels through sun exposure Some evidence links vitamin D deficiency to a higher risk of certain cancers, immune diseases, and cardiovascular disease. High vitamin D blood levels generally result from taking too many vitamin pills andHigh doses of vitamin D can result in a