25-hydroxy vitamin D test

  • Alternative Names

    25-OH vitamin D test; Calcidiol 25-hydroxycholecalciferol test

    Normal Values

    The normal range is 30.0 to 74.0 nanograms per milliliter (ng/mL).

    Note: Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

    What abnormal results mean

    Lower than normal levels suggest a vitamin D deficiency. This condition can result from:

    • Lack of exposure to sunlight
    • Lack of adequate vitamin D in the diet
    • Liver and kidney diseases
    • Malabsorption
    • Use of certain medicines, including phenytoin, phenobarbital, and rifampin

    Low vitamin D levels are more common in African-American children, particularly in the winter, as well as in infants who are exclusively breastfed. Low vitamin D levels have also been associated with an increased risk of developing cancer. For more information, see the article on vitamin D deficiency.

    Higher than normal levels suggest excess vitamin D, a condition called hypervitaminosis D.