Vitamin D Blood Tests measure the level of 25(OH)D (25 HydroxyVitamin D) in your blood. Lower or higher than normal levels of Vitamin D could indicate nutritional problems, organ damage, bone disorders or other medical conditions, such as Crohn’s disease or ulcerative colitis.
Vitamin D is essential for healthy bones and teeth. There are two forms of Vitamin D which are vital for nutrition: Vitamin D2 and Vitamin D3.
Vitamin D2 is often found in fortified foods, such as cereals, milk, mushrooms, yeast and some dairy items.
Vitamin D3 is produced by the body when it is exposed to sunlight, however, it is also found in some foods, such as oily fish (tuna, salmon, mackerel to name a few), eggs and liver.
When they enter your bloodstream, both Vitamin D2 and Vitamin D3 become a form of Vitamin D called 25 HydroxyVitamin D, otherwise known as 25(OH)D.
Vitamin D Blood tests measure the level of 25(OH)D in order to screen or monitor bone disorders. Additionally, the tests are sometimes conducted in order to check the levels of Vitamin D in patients with chronic illnesses, such as certain autoimmune diseases, psoriasis, and asthma.
The normal range of Vitamin D is measured as nanograms per millilitre (ng/mL) and the recommended level of Vitamin D lies between 20 and 50 ng/mL.
While routine Vitamin D tests are not usually recommended, a medical professional may refer you for a blood test should you have any symptoms of a Vitamin D deficiency.
These symptoms could include:
- Unexplained fracturesBone softness
- Bone malformation
- Bone weakness
You may also be referred for a blood test if you are considered at an elevated risk for a Vitamin D deficiency. Those at elevated risk include patients who:
- have osteoporosis or other bone disorders
- have previously had gastric bypass surgery
- are over the age of 65, as adults are more likely to be Vitamin D deficient
- are obese
- have had a lack of exposure to sunlight
- a darker complexion
- struggle to absorb the fat in their diet
- have problems absorbing vitamins and nutrients in their intestines, such as patients who suffer from ulcerative colitis, Crohn’s disease, or celiac disease.
What do the results mean?
Should the blood test indicate a deficiency in Vitamin D, it may mean that the patient’s body is having difficulty using the vitamin as it should, and may indicate kidney or liver disease. A Vitamin D deficiency is usually treated with supplements and/or dietary changes.
Should the blood test indicate that the levels of Vitamin D are high, this would most likely be due to an excess of vitamin pills or supplements. Be sure to tell your health care provider about medicines, vitamins, or supplements you are taking, because they can affect your test results.
The Vitamin D Testing Process
A health care professional will take a small sample of your blood and collect it into a vial or test tube. The entire process lasts approximately five minutes.
You won’t need to prepare anything before the blood test, however, please ensure you tell your healthcare provider about any medicines, vitamins, or supplements you are taking, as these can affect the results.
To find out more about our blood tests, including the Vitamin D testing, please contact us via our contact form, or give us a call.
