LC–MS/MS based 25(OH)D status in a large Southern European outpatient cohort: gender- and age-specific differences

Background Developed countries have a high prevalence of vitamin D deficiency. In previous studies, 25(OH)D was predominantly measured by immunoassays. The present study assessed serum 25(OH)D in a very large Southern European outpatient cohort by liquid chromatography tandem mass spectrometry (LC–MS/MS).