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A vitamin D test measures the amount of vitamin D in the blood. Your body needs vitamin D to absorb calcium. Calcium keeps your bones and muscles healthy and strong.
If your muscles don't get enough calcium, they can cramp, hurt, or feel weak. You may have long-term (chronic) muscle aches and pains. If you don't get enough vitamin D throughout life, you are more likely to have thin and brittle bones (osteoporosis) in your later years.
Children who don't get enough vitamin D may not grow as much as others their age. They also have a chance of getting a rare disease called rickets.
Your body uses sunshine to make its own vitamin D. Vitamin D is found in foods such as egg yolks, liver, and saltwater fish. It is also added to many food products, such as milk, orange juices, yogurts, margarines, and soy beverages. You can also get it as a natural health product, often combined with calcium.
Vitamin D recommendations vary from province to province. Talk with your doctor about how much vitamin D you need. Health Canada and Osteoporosis Canada recommend that Canadian adults take daily vitamin D supplements.
The vitamin D test is also called the 25-hydroxy vitamin D, or 25(OH)D, test.
In Alberta, you can only get this blood test if you have a medical condition that could be affected by low levels of vitamin D. This includes medical conditions such as:
Most healthy Albertans don’t need a vitamin D test. Vitamin D test results likely won’t change the advice from your healthcare provider. What’s important is that you try to get enough vitamin D from the sun, foods, and supplements. To learn more about vitamin D supplements and other sources of vitamin D, talk to your healthcare provider or see:
There is nothing to do to prepare for this test.
Your health professional drawing blood will:
The blood sample is taken from a vein in your arm. An elastic band is wrapped around your upper arm. It may feel tight. You may feel nothing at all from the needle, or you may feel a quick sting or pinch.
There is very little chance of a problem from having a blood sample taken from a vein.
A vitamin D test measures the amount of vitamin D in the blood.
The normal values listed here—called a reference range—are just a guide. These ranges vary from lab to lab, and your lab may have a different range for what's normal. Your lab report should contain the range your lab uses. Also, your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed here may still be normal for you or your lab.
50–150 nanomoles per litre (nmol/L) or 30–80 nanograms per millilitre (ng/mL)
High levels of vitamin D can be caused by:
Low levels of vitamin D can be caused by:
Medicines that may decrease vitamin D levels include:
CitationsPagana KD, Pagana TJ (2011). Vitamin D (25-hydroxy vitamin D). In Mosby's Manual of Diagnostic and Laboratory Tests, 4th ed., pp. 543–547. St. Louis: Mosby.
Adaptation Date: 5/5/2021
Adapted By: Alberta Health Services
Adaptation Reviewed By: Alberta Health Services
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