Within this project, additional parameters of calcium–phosphate metabolism, such as non-oxidised parathyroid hormone (noxPTH), calcidiol, vitamin D binding protein (VDBP), and fibroblast growth factor 23 (FGF23) were evaluated in a control population of 177 individuals as well as 182 patients with renal, gastroenterological, and liver diseases. Here, PTH is linked to liver disorder.