Vitamin D test: who needs one?
A vitamin D blood test is not a routine screening for healthy adults. The USPSTF found the evidence insufficient to recommend for or against it, and the Endocrine Society suggests against routine testing. Doctors still test when there are symptoms, a related condition or a high risk. Your doctor decides. (USPSTF, 2021) (Endocrine Society, 2024) (MedlinePlus, 2024)
What each body says
The bodies differ in wording but agree that healthy adults do not need a routine test.
| Body | Position |
|---|---|
| USPSTF (2021, final) | Adults living at home, not pregnant, with no signs of deficiency such as bone pain or muscle weakness: evidence insufficient to weigh benefits and harms of screening (I statement) (USPSTF, 2021) |
| Endocrine Society (2024) | Suggests against routine testing in healthy adults, at ages under 50, 50 to 74 and 75 and older, in pregnancy, and in adults with dark complexion or with obesity; this does not apply to people with an established reason to test, such as low blood calcium (Endocrine Society, 2024) |
| MedlinePlus (NIH) | Routine vitamin D testing is not recommended for everyone (MedlinePlus, 2024) |
The 2024 Endocrine Society guideline replaces its 2011 guideline, which, as the USPSTF summarized it in 2021, recommended screening people at risk. (Endocrine Society, 2024) (USPSTF, 2021) An I statement means the evidence is insufficient; it is not advice against a test your doctor orders. More: USPSTF grades explained.
When doctors test anyway
- A condition that may be linked to very low vitamin D, such as osteomalacia (soft bones), low bone density or osteoporosis. (MedlinePlus, 2024)
- Symptoms such as bone pain, muscle weakness or aches, or weak bones and fractures. (MedlinePlus, 2024)
- A high risk of deficiency: rarely getting sun on the skin, not eating enough, weight loss surgery, conditions that make it hard to absorb nutrients (Crohn's disease, ulcerative colitis, celiac disease), kidney or liver disease, or medicines that affect vitamin D, including certain statins, steroids and weight-loss medicines. (MedlinePlus, 2024)
- To check whether treatment for deficiency is working, or when symptoms suggest too much vitamin D from supplements. (MedlinePlus, 2024)
What the results mean, in plain words
Most tests measure 25-hydroxyvitamin D, written 25(OH)D, the form that best shows whether you have enough. Results are usually described as deficient, insufficient, sufficient or toxic. A low result may mean too little vitamin D from food and sun, trouble absorbing it, kidney or liver disease, or a medicine; a very high result usually comes from too many supplements. (MedlinePlus, 2024)
No single level defines deficiency, and there is no consensus on the level that means optimal health. According to the National Academy of Medicine, as summarized by the USPSTF, a level of 20 ng/mL (49.9 nmol/L) meets the needs of an estimated 97.5% of people, and the risk of deficiency for bone health begins below 12 to 20 ng/mL. In US survey data from 2011 to 2014, 5% of people aged 1 and older had levels below 12 ng/mL. (USPSTF, 2021) Your doctor reads your result with your symptoms and history.
Questions people ask
Should I get my vitamin D level checked?
Not as a routine screening if you are healthy and have no symptoms. The USPSTF found the evidence insufficient to recommend for or against it (I statement, 2021), and the Endocrine Society suggests against routine testing in healthy adults (2024). Your doctor may test for a reason that applies to you. (USPSTF, 2021) (Endocrine Society, 2024)
Should I get tested if I have darker skin or obesity?
The Endocrine Society 2024 guideline suggests against routine vitamin D testing in otherwise healthy adults with dark complexion or with obesity, and during pregnancy, unless there is another reason to test. (Endocrine Society, 2024)
What vitamin D level is normal?
There is no single agreed cutoff. The USPSTF notes that, according to the National Academy of Medicine, a level of 20 ng/mL meets the needs of an estimated 97.5% of people, and the risk of deficiency for bone health begins below 12 to 20 ng/mL. Labs report results as deficient, insufficient, sufficient or toxic. Your doctor reads your result. (USPSTF, 2021) (MedlinePlus, 2024)
Why do doctors still order vitamin D tests?
Mostly when a bone or other condition may be caused by very low vitamin D, when there are symptoms such as bone pain or muscle weakness, or when risk is high, for example after weight loss surgery, with Crohn's or celiac disease, kidney or liver disease, or with some medicines. (MedlinePlus, 2024)