Retinol Depletion in Severe COVID-19

Sarohan, A. R.; Akelma, H.; Arac, E.; Aslan, O.

Background and Purpose: Vitamin A is depleted during infections. Vitamin A has been used successfully in measles, RSV, and AIDS patients and is an effective vaccine adjuvant. In this study, low retinol levels were found in patients with severe COVID-19. Retinoid signaling impairment in COVID-19 disrupts Type-I interferon synthesis. Material and Method: Two groups were formed in the study. The patient group consisted of 27 (Group 1) severe COVID-19 patients hospitalized in the intensive care unit with respiratory failure, and the control group consisted of 23 (Group 2) patients without COVID-19 symptoms. Serum retinol levels were analyzed by ELIZA and HPLC in both groups. Findings: Retinol levels were found to be significantly lower in the patient group (P <0.001). There was no difference in retinol between two different age groups in the patient group (P> 0.05). There was no significant difference in retinol between men and women (P> 0.05). Comorbidity did not affect serum retinol levels (P >0.05). Conclusion: Serum retinol levels were low in patients with severe COVID-19. Drugs preventing retinol excretion were not stopped in the patient group. Some patients took vitamin A externally. Despite this, retinol was low in COVID-19 patients. Retinol depletion impairs Type-I interferon synthesis by impairing retinoid signaling. Retinoid signaling may be the main pathogenetic disorder in COVID-19. This pathogenesis can serve as a guide for adjuvants, drug targets, and candidate drugs. Retinol, retinoic acid derivatives, and some CYP450 inhibitors may work on COVID-19.