Testing and measurement of Vitamin D

A vital nutrient, vitamin D, affects immune system performance, bone health, and the prevention of chronic diseases. Clinical and scientific applications require precise measurement of vitamin D metabolites. This chapter explores the many approaches of vitamin D analysis, emphasizing their fundamentals, uses, and drawbacks. The first section covers the therapeutic importance of vitamin D metabolites, including 1,25-dihydroxyvitamin D and 25-hydroxyvitamin D. A worldwide summary of the underutilization of vitamin D testing techniques is provided, with a focus on inequalities and implementation difficulties. Alongside developments in Chemiluminescence Immunoassays and the gold-standard liquid chromatography-tandem mass spectrometry, conventional methods such as competitive protein binding assays, high-performance liquid chromatography, radioimmunoassay, and enzyme-linked immunosorbent assay are investigated. New techniques that promise improved sensitivity and specificity include capillary electrophoresis and supercritical fluid chromatography. Examined are developments in biosensors and point-of-care testing, which have the potential to completely transform the affordability and accessibility of vitamin D testing. The chapter concludes with an outlook on how these approaches might be combined with new technology to improve vitamin D analysis, filling in existing gaps and opening the door to better patient treatment and public health results.