What it is
Most vitamin D blood tests measure 25-hydroxyvitamin D, the form commonly used to assess vitamin D status.[1]
Why it matters
Vitamin D context matters for calcium absorption and mineralization; severe deficiency can be part of osteomalacia or rickets.[2,1]
What it affects
- A low value may prompt clinicians to look for deficiency, malabsorption, limited intake, limited sunlight exposure, kidney context, or other causes.[2]
Interpretation traps
- This page does not give supplement doses or universal target ranges; lab method, kidney disease, and clinical context matter.[1]