Enter your serum 25-hydroxyvitamin D [25(OH)D] result and get an evidence-based interpretation against the IOM and Endocrine Society reference ranges. Educational only — not medical advice.
= 32.0 ng/mL · 80.0 nmol/L
A serum 25(OH)D between 30 and 50 ng/mL (75–125 nmol/L) is considered sufficient for musculoskeletal health by both the IOM and the Endocrine Society, and is the target range for most healthy adults.
Suggested action
No change indicated. Maintain your current sun exposure and supplementation routine. Consider seasonal re-testing at the end of winter to catch any winter decline.
Not medical advice
Serum 25(OH)D thresholds are guidelines derived from population studies. Individual management depends on symptoms, comorbidities, medications, and other laboratory values (calcium, phosphorus, PTH, creatinine). Always discuss results with your healthcare provider.
The blood test used to assess vitamin D status measures the concentration of 25-hydroxyvitamin D — the metabolite produced when the liver hydroxylates cholecalciferol (D3) or ergocalciferol (D2). It is preferred over measuring cholecalciferol directly because 25(OH)D has a long enough half-life to reflect several weeks of cumulative status, and over 1,25-dihydroxyvitamin D (calcitriol) because calcitriol is tightly regulated by PTH and doesn't reflect body stores.
Results are reported in either ng/mL (nanograms per millilitre, common
in the US) or nmol/L (nanomoles per litre, common in Europe, Canada,
Australia). The conversion is 1 ng/mL = 2.5 nmol/L.
The two major guideline bodies — the Institute of Medicine and the Endocrine Society — set slightly different thresholds. The IOM defines sufficiency at ≥ 20 ng/mL (50 nmol/L); the Endocrine Society at ≥ 30 ng/mL (75 nmol/L). Both agree that levels below 12 ng/mL (30 nmol/L) constitute severe deficiency, and that sustained levels above 100 ng/mL (250 nmol/L) approach the toxic range.