Vitamin D
25-hydroxyvitamin D
Low
25.4ng·mL⁻¹Ref 30–100 ng·mL⁻¹
Z -2.26↓ Bad

The card shows an example result of 25.4 ng·mL⁻¹, which is 2.26 SD below the mean.

What it measures

25-hydroxyvitamin D is made in the liver from vitamin D from sunlight, food, and supplements. It is the stored form the body draws on.

Reference range

FieldValue
AbbreviationVitamin D
GroupBone and mineral
Unitng·mL⁻¹
Healthy range30–100
Mean65
SD17.5
Direction↓ Bad — a lowered value is the concern.

The mean is (low + high) / 2 and the SD is (high − low) / 4, so the healthy range covers Z from −2 to +2.

Reading the result

  • High — Not the concern this panel tracks. Very high values, above about 150 ng·mL⁻¹, usually come from too many supplements and can raise calcium.
  • Low — Points to vitamin D insufficiency. It is linked to weaker bones, muscle weakness, and a raised PTH.

Notes

  • To convert to nmol·L⁻¹, multiply by 2.5.
  • Levels are lower in winter and with darker skin, less sun, or obesity.
  • This page is general information, not medical advice. Discuss results with a clinician.