Vitamin D Test: Normal Range and What It Means

The 25-hydroxyvitamin D blood test is the standard way to measure vitamin D status, reflecting both what you get from sun exposure and from diet or supplements.

Interpreting the Result

• Deficient: generally below 20 ng/mL
• Insufficient: generally 20–29 ng/mL
• Sufficient: generally 30 ng/mL or higher

Exact cutoffs can vary slightly between laboratories and guidelines, which is part of why a doctor's interpretation matters more than comparing your number to a single fixed chart. The 30 ng/mL threshold above reflects a 2011 Endocrine Society clinical guideline often applied to patients at higher risk of deficiency, while general population-health guidance considers roughly 20 ng/mL adequate for most healthy people — and the Endocrine Society's updated 2024 guideline moved away from recommending routine testing or a single fixed cutoff for the general population, which is part of why individual risk factors matter more than one universal number.

When It's Typically Ordered

Doctors commonly order this test for people with symptoms suggestive of deficiency, those with risk factors (limited sun exposure, darker skin, obesity, certain digestive conditions that affect absorption, or older age), or as part of general health screening in regions where deficiency is common.

After the Result

A confirmed deficiency or insufficiency typically leads to a discussion about supplementation, sun exposure, and dietary sources — see our best sources of vitamin D and vitamin D dosage guides — with follow-up testing to confirm the level has improved.