Vitamin D receptor polymorphisms and vitamin D insufficiency are not associated with sepsis in critically ill children: a case-control study

Abstract Background Vitamin D is a fat-soluble vitamin that regulates calcium and phosphorous homeostasis to maintain a healthy mineralized skeleton. It can also influence immune responses and has immunomodulatory properties. Vitamin D receptor (VDR) is a nuclear receptor that mediates the activities of the hormonal form of vitamin D. VDR polymorphisms can alter immunity and susceptibility to infections by modulating VDR expression and vitamin D activity. This study aimed to investigate the levels of serum vitamin D as well as four VDR polymorphisms: FokI, BsmI, ApaI, and TaqI in fifty children admitted to intensive care unit (ICU) with a diagnosis of sepsis and one-hundred age- and sex-matched healthy children. Methods Vitamin D levels were measured in serum, in both patients and controls, using an enzyme-linked immunosorbent assay (ELISA) approach. VDR polymorphisms were also studied in both groups using specific restriction enzymes. Results Vitamin D levels were low in both patients and controls. Moreover, serum levels were unaffected by VDR polymorphisms, and their distribution was similar in both groups. Neither the need for mechanical ventilation or inotropic treatment nor the sepsis outcome was impacted by serum vitamin D levels or VDR polymorphisms. Conclusion In children admitted to pediatric ICU, neither vitamin D levels nor VDR polymorphisms were associated with sepsis. Further larger studies including different types of sepsis are recommended.