The association between vitamin D3 deficiency and acute kidney injury in COVID-19 patients

Introduction: Vitamin D deficiency is a common clinical finding in the general population and hospitalized patients, including patients in the intensive care unit (ICU). Acute kidney injury (AKI) occurs in more than 50% in ICU admitted patients. Objectives: There are few studies regarding AKI in COVID-19 patients, therefore we investigated the relationship between vitamin D3 deficiency and the occurrence of AKI in COVID-19 patients. Patients and Methods: This cross-sectional study was conducted on 69 COVID-19 patients who were hospitalized in the ward for 12 months. Their serum vitamin D3 levels were measured in the first 24 hours of hospitalization in the ward. Patients were divided into three groups based on the serum levels of vitamin D3: >50 ng/mL as normal, 20-50 ng/mL as insufficient and <20 ng/mL as deficiency status. The patients were studied until the occurrence of acute renal injury or the occurrence of death. Results: Out of 69 hospitalized patients in the ward with COVID-19, there were 39 patients in group vitamin D3<20 ng/mL, 21 patients in group vitamin D3 of 20-50ng/mL and 9 patients in group of vitamin D3>50 ng/mL. The frequencies of AKI in groups of vitamin D3<20 ng/mL, 20-50 ng/mL, and >50 ng/mL were 46%, 28%, and 23%, respectively. A significant relationship was observed between AKI and our study groups (P=0.011). Furthermore, there was a significant association between our study groups and mortality (P=0.014), ICU admission (P=0.041) and hospital length of stay (P=0.017). In another division in patients with different levels of vitamin D3 in the presence or absence of AKI, there were significant associations between patients with vitamin D3<20 ng/mL and the presence of AKI and also with mortality (P=0.042), ICU admission (P=0.024) and additionally with hospital length of stay (P=0.027). Conclusion: Our study showed significant association between vitamin D deficiency and AKI in ICU-admitted COVID-19 patients. Moreover, there were relationships between vitamin D deficiency and mortality, ICU admission and hospital length of stay. These results suggest the correction of vitamin D deficiency may be beneficial to reduce AKI in patient with COVID-19.