Recent trends in the analysis of vitamin D and its metabolites in milk--a review.

Vitamin D plays an important role in calcium metabolism and affects other metabolic pathways. Despite the intense interest in vitamin D, no comprehensive overview addressing the analysis of vitamin D in milk has been published. Historically, immunoassay techniques have been mainly used for the routine quantification of vitamin D and its metabolites. However, the greater accuracy and precision of chromatography makes it one of the most important methods in the analysis of vitamin D. The determination of vitamin D and its metabolites by LC-MS is the gold standard for its assessment. LC-MS has unique advantages for vitamin D determination and quantification due to its high sensitivity and specificity. In this review, the current status of vitamin D and its metabolites analysis in milk, human and bovine, including sample pre-treatment and chromatography analysis, are critically discussed and summarised.