A fast and simple method for simultaneous measurements of 25(OH)D, 24,25(OH)2D and the Vitamin D Metabolite Ratio (VMR) in serum samples by LC-MS/MS

We present a rapid, easy, reliable and cost-effective method completely adequate for routine testing, which permits the measurement of the ratio of 24,25-dihydroxyvitamin D to 25-hydroxyvitamin D, Vitamin D Metabolite Ratio (VMR), in serum samples.