Cholecalciferol level and its impact on COVID-19 patients

Cholecalciferol 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.

Our 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 D₃ level (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 D₃ was correlated to the length of stay mechanical ventilation days and mortality.

Lower level of vitamin D₃ on 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 with P value < 0.001.Also, when correlating the initial level of vitamin D₃ on 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 D₃ level on admission and ferritin level on fifth day ρ-0.739 p value < 0.001 also on the tenth day ρ-0.885, P value < 0.001, in comparing also with D-dimer on fifth day ρ-0.858, p value < 0.001 also showing a strong inverse correlation with a highly significant p value this also evident on the D-dimer level on the tenth day ρ-0.889 with p value < 0.001, CRP at fifth and tenth day ρ-0.868, P value < 0.001, ρ-0.891, P value < 0.001 respectively also in correlating the LDH level on the fifth and tenth day with the initial level of vitamin D₃ it shows a strong inverse correlation with a highly significant p value. ρ-0.887, P value < 0.001, ρ-0.878, p value < 0.001 respectively, in the fifth and tenth day. Neutrophil to lymphocyte ratio was strongly, inversely correlated to the vitamin D₃ level (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, p value < 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 D₃ to 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.

Low level of cholecalciferol was strongly inversely correlated with cytokine storm markers and independent predictor of severity and mortality in COVID-19 patients.