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.

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.