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