Why is a vitamin D test done?
You may need this test if you:
- Have low levels of calcium or phosphate.
- Have osteoporosis or low bone density.
- Had a broken bone after a fall from standing, such as if you trip and fall. The break most commonly occurs in the hip or wrist.
- Have gone through menopause and worry about osteoporosis.
- Have low levels of vitamin D.
How is a vitamin D test done?
A health professional uses a needle to take a blood sample, usually from the arm.
How do you prepare for a vitamin D test?
In general, there’s nothing you have to do before this test, unless your doctor tells you to.
What do the results of a vitamin D test mean?
Normal
Each lab has a different range for what’s normal. Your lab report should show the range that your lab uses for each test. The normal range is just a guide. Your doctor will also look at your results based on your age, health, and other factors. A value that isn’t in the normal range may still be normal for you.
High values
High levels of vitamin D can be caused by:
- Williams syndrome. This is a genetic problem that causes growth delays before and after birth.
- Taking too many vitamin D supplements.
Low values
Low levels of vitamin D can be caused by:
- Kidney disease.
- Liver disease.
- Not getting enough sunlight.
- Not getting enough vitamin D in your diet.
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