Vitamin A and SARS-CoV2 infection: roles in host resistance and recovery from infection

Authors: Stephensen, Charles; LIETS, GEORGE - Newcastle University

Submitted to: British Journal of Nutrition
Publication Type: Review Article
Publication Acceptance Date: 1/20/2021
Publication Date: 1/20/2021
Citation: Stephensen, C.B., Liets, G. 2021. Vitamin A in resistance to and recovery from infection: relevance to SARS-CoV2. British Journal of Nutrition. 1-10. https://doi.org/10.1017/S0007114521000246.
DOI: https://doi.org/10.1017/S0007114521000246

Interpretive Summary: SARS-CoV2 is a coronavirus that entered the human population in 2019, causes the disease called COVID-19 and is causing a worldwide pandemic in 2020. Many viral infections that cause severe disease can adversely affect vitamin A status by a variety of pathways, including decreased absorption, increased utilization, altered metabolism and storage, and loss in the urine due to impaired kidney function. While vitamin A deficiency is not common in the U.S., COVID-19 could cause a functional vitamin A deficiency that may need to be corrected with vitamin A supplementation during recovery from COVID-19. Vitamin A may be particularly important in recovery from COVID-19 for several reasons. First, vitamin A is important in maintaining normal immune function that is important for clearing infection with SARS-CoV2. Second, vitamin A plays a unique role in the respiratory tract, minimizing damaging inflammation and supporting repair of respiratory epithelium and preventing fibrosis during recovery, which compromises lung function. Third, vitamin A deficiency may develop during COVID-19 due to specific effects on lung and liver stores caused by inflammation and impaired kidney function, suggesting that supplements may be needed to restore adequate status. Fourth, vitamin A supplementation may counteract adverse effects of SARS-CoV2 on the angiotensin system, which is affected during COVID-19, as well as minimizing adverse effects of some COVID-19 therapies on immune function and repair of lung tissue. Evaluating interactions of SARS-COV2 infection with vitamin A metabolism may thus provide improvements to COVID-19 therapy.

Technical Abstract: SARS-CoV2 infects respiratory epithelial cells via its cellular receptor angiotensin-converting enzyme 2 (ACE2), causing a viral pneumonia with pronounced inflammation resulting in significant damage to the lungs and other organ systems, including the kidneys. The resulting disease, COVID-19, has a prolonged course in about 5% of cases, requiring hospitalization, intensive care treatment and has a 50% mortality rate. Therapeutic interventions are under development and may have significant side effects. Serious infections like COVID-19 often have negative effects on nutritional status and the resulting nutritional deficiencies may increase severity of the infection and impair recovery. One example is the viral infection measles, where associated vitamin A (VA) deficiency increases disease severity and appropriately timed VA supplementation during recovery reduces mortality and hastens recovery. VA may play a similar role in COVID-19. First, VA is important in maintaining innate and adaptive immunity to promote clearance of a primary infection as well as minimize the risk from secondary infections. Second, VA plays a unique role in the respiratory tract, minimizing damaging inflammation and supporting repair of respiratory epithelium and preventing fibrosis. Third, VA deficiency may develop during COVID-19 due to specific effects on lung and liver stores caused by inflammation and impaired kidney function, suggesting that supplements may be needed to restore adequate status. Fourth, VA supplementation may counteract adverse effects of SARS-CoV2 on the angiotensin system as well as minimizing adverse effects of some COVID-19 therapies. Evaluating interactions of SARS-COV2 infection with VA metabolism may thus provide improvements to COVID-19 therapy.