Vitamins (B1, B2, B6, B8, B9, B12, C, 25OH D, A and E, K…) are often assayed by HPLC or UPLC to detect deficiencies or overloads.
According to the HAS (Haute Autorité de Santé; French National Authority for Health), their levels should be monitored in patients after surgery, especially digestive surgery (such as bariatric surgery), and in those suffering from certain pathologies (cystic fibrosis, neuropathies), in order to detect, treat and avoid deficiencies. These assays usually include zinc, and occasionally copper, selenium or iodine. In addition, vitamins are prescribed for the treatment of several metabolic disorders, and their levels may need to be monitored as well.
The morpho-constitutional analysis and Fourier transform infrared spectroscopy of urinary stones identify and quantify the different components, and this biological assessment is used by clinicians to elucidate the aetiology.
Several metabolic syndromes are investigated and monitored using ion exchange chromatography for amino acids, gas chromatography mass spectrometry (GC-MS) for organic acids, as well as HPLC and colorimetry for porphyria. The Wilson disease is screened and monitored using a combination of copper assays in plasma and urinary by ICP-MS and the immunochemical analysis of ceruloplasmin. All these techniques, HPLC, UPLC, GC MS, LC MSMS, ICP MS, the analysis of urinary stones and the investigation of metabolic syndromes, require specialised technicians who become qualified after a long training period.