25(OH)D
Medical abbreviation · Laboratory Test
| Stands for | 25-hydroxyvitamin D |
|---|---|
| Categories | Medical |
25(OH)D stands for 25-hydroxyvitamin D, a laboratory test abbreviation.
Main circulating form of vitamin D and the standard test of vitamin D status, reported in ng/mL in the US or nmol/L elsewhere. Many labs flag levels below 20 ng/mL (50 nmol/L) as deficient, though optimal targets remain debated among expert bodies.
Example: 25(OH)D 9 ng/mL in a housebound patient with bone pain; high-dose replacement started.
Usage notes
Written 25-OH vitamin D or calcidiol. To convert ng/mL to nmol/L, multiply by 2.5. The active hormone, 1,25-dihydroxyvitamin D, is a poor measure of stores and is reserved for specific conditions such as kidney disease and granulomatous disorders. A 2024 Endocrine Society guideline advises against routine testing in healthy adults.
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This entry is for general education and is not medical advice. Abbreviation use varies between institutions; always confirm in context.