Impact of Vitamin D in Chronic Kidney Disease and Its Effect on the Musculoskeletal System

Introduction. Vitamin D plays an important role in maintaining musculoskeletal health. As the glomerular filtration rate decreases, vitamin D deficiency also occurs. The aim of this paper is to highlight the level of vitamin D depending on the stage of chronic kidney disease. Materials and methods. A structured search was performed in the PubMed, Scopus and HINARI databases, where the relevant articles have been taken into account, published in the last 20 years. The search terms used (in English) were: „vitamin D deficiency”, „pathogenesis of vitamin D”, ”the impact of vitamin D in chronic kidney disease”, „chronic kidney disease”. Results. Several studies have shown that the change in vitamin D levels is dependent to the decrease of glomerular filtration rate. The lowest serum vitamin D concentration was observed in stage 5 of chronic kidney disease. Vitamin D deficiency occurs due to a decrease in the number of nephrons and a decrease in the number of proximal tubular cells that absorb vitamin D (25 (OH) D) to be subsequently hydroxylated to its active form by 1α-hydroxylase. Conclusions. Patients with vitamin D-deficient due to chronic kidney disease have an increased risk of decreased bone mineral density and multiple fractures.