Question 10. What are the sources of vitamin D? Question 11. What impact do the seasons have on vitamin D levels? Question 12. Who should be tested for vitamin D levels? Question 13. What does vitamin D testing measure? Question 14. How does Quest Diagnostics test for vitamin D?
WO 2011/122948 (Future Diagnostics BV) discloses a release of vitamin D metabolites in serum samples using a fluorine-containing surfactant such as perfluorooctanoic acid. U.S. Pat. No. 7,745,226 B2 (Clarke et al.) teaches a combination of liquid chromatography and mass spectrometry for ...