Cholecalciferol level and its impact on COVID-19 patients
Authors: Saeed Mohammed Abdel Monem , Mohamed Alaa Hussein , Owaynat Ahmed Hassan 
Published: February 2022

AbstractBackgroundCholecalciferol is an important nutrient and essential to build body, maintain strong bones, and improves immunity.The main source for vitamin D is the body’s skin which absorbs the sun’s ultraviolet rays and convert them into vitamin D; at the same time, deficiency can occur or people may not get enough supplementation; this occurs mainly in old age, not taking healthy food, or have darker skin, and this deficient cases can raise the risk of severe COVID-19 if infected.Vitamin D boosts immunity and decreases inflammation. Poorer outcome of corona virus—disease (COVID-19) has been suggested to be due to vitamin D deficiency.We suggested to find the effect of cholecalciferol levels 25-hydroxy vitamin D (25 OHD) on the severity and mortality in patients suffering from COVID-19.MethodsOur study is a prospective following of 414 patients admitted in Helwan University Hospitals in the period of June 2020 till October 2021 for severely symptomatic. COVID-19 patients with median of age 54.55 ± 14.27, with a definite range of APACHE II score ranging from 15 to 19 where we measured vitamin D3level (cholecalciferol level), correlating the assay level to the inflammatory cytokine storm markers on admission, on the fifth day and after 10 days also the level of vitamin D3was correlated to the length of stay mechanical ventilation days and mortality.ResultsLower level of vitamin D3on admission was strongly evident in patients with severely symptomatic and in mortality of COVID-19 patients 58.25 ± 24.59 nmol/L when compared with patients who survived 103.97 ± 36.14 nmol/L withPvalue < 0.001.Also, when correlating the initial level of vitamin D3on admission with the level of the inflammatory cytokine storm markers on admission, on fifth day from admission and on the tenth day, it shows a strong inverse correlation between vitamin D3level on admission and ferritin level on fifth day ρ–0.739pvalue < 0.001 also on the tenth day ρ–0.885,Pvalue < 0.001, in comparing also with D-dimer on fifth day ρ–0.858,pvalue < 0.001 also showing a strong inverse correlation with a highly significantpvalue this also evident on the D-dimer level on the tenth day ρ–0.889 withpvalue < 0.001, CRP at fifth and tenth day ρ–0.868,Pvalue < 0.001, ρ–0.891,Pvalue < 0.001 respectively also in correlating the LDH level on the fifth and tenth day with the initial level of vitamin D3it shows a strong inverse correlation with a highly significantpvalue. ρ–0.887,Pvalue < 0.001, ρ–0.878,pvalue < 0.001 respectively, in the fifth and tenth day. Neutrophil to lymphocyte ratio was strongly, inversely correlated to the vitamin D3level (cholecalciferol) on admission with ρ–0.753,p< 0.001, ρ–0.882,P< 0.001 respectively. Also, chest computed tomography in the fifth and tenth day of admission showed a very strong inverse correlation with vitamin D level and a highly significant statistical difference ρ–0.655,pvalue < 0.001 respectively.Length of stay and mechanical ventilation days were also strongly inversely correlated to the cholecalciferol level ρ–0.795,p< 0.001, ρ– 0.879,P< 0.001 ROC curve of vitamin D3to predict mortality (RR 0.865, 95% CI 0.828–0.896,P< 0.001, with cut off-value for vit. D3< 60 nmol/L, regardless of other factors like age, gender, and presence of other co-morbidities.ConclusionLow level of cholecalciferol was strongly inversely correlated with cytokine storm markers and independent predictor of severity and mortality in COVID-19 patients.