25-Hydroxyvitamin D Level Interpretation
Reads a serum 25-hydroxyvitamin D level against the two frameworks that disagree about it, and returns both.
Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.
Example
- Serum 25-hydroxyvitamin D
- 25
- Units of the entered level
- ng/mL
Result: 25 ng/mL: adequate by one framework and insufficient by the other
The tool opens with these values already filled in. Replace them with your own.
What the result means
- Institute of Medicine
- Below 12 ng/mL is deficiency. 20 ng/mL meets the needs of at least 97.5 percent of the population for bone health.
- Endocrine Society
- Below 20 ng/mL is deficiency, 21 to 29 is insufficiency, and 30 or above is sufficiency.
- Where they disagree
- Between 20 and 29 ng/mL. The Institute of Medicine reads that as adequate and the Endocrine Society as insufficient, and neither is quoted here as the answer.
- The 20 ng/mL figure
- A population reference derived to cover 97.5 percent of people for bone health. Not an individual treatment target, though it is routinely read as one.
- Whether to test at all
- The 2024 Endocrine Society guideline recommends against routine testing in healthy adults: no threshold reliably guides supplementation without an indication.
- The assay
- Total 25-hydroxyvitamin D moves with binding protein and varies between laboratories, so a value near a threshold does not separate cleanly from the other side.
What you enter
- Serum 25-hydroxyvitamin D
- Units of the entered level
How this is calculated
Institute of Medicine. Dietary Reference Intakes for Calcium and Vitamin D. National Academies Press; 2011. Demay MB, Pittas AG, Bikle DD, et al. Vitamin D for the Prevention of Disease: an Endocrine Society Clinical Practice Guideline. J Clin Endocrinol Metab. 2024;109(8):1907-1947. Read the source ↗
A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.