Vitamin A in resistance to and recovery from infection: relevance to SARS-CoV2
Stephensen et al.
, Vitamin A in resistance to and recovery from infection: relevance to SARS-CoV2
, British Journal of Nutrition, doi:10.1017/S0007114521000246 (Review)
Review of the potential benefits of vitamin A for COVID-19, including maintaining innate and adaptive immunity, minimizing inflammation, supporting repair of respiratory epithelium and preventing fibrosis, and counteracting adverse effects of SARS-CoV-2 on the angiotensin system.
Stephensen et al., 20 Jan 2021, peer-reviewed, 2 authors.
Abstract: Vitamin A in resistance to and recovery from infection: relevance to SARS-CoV2
C. B. Stephensen1* and G. Lietz2*
Immunity and Disease Prevention Research Unit, USDA Western Human Nutrition Research Center, and Nutrition
Department, University of California, Davis, CA, USA
Human Nutrition Research Centre, Population Health Sciences Institute, Newcastle University, Newcastle upon
Tyne NE2 4HH, UK
(Submitted 12 September 2020 – Final revision received 30 December 2020 – Accepted 13 January 2021)
SARS-CoV2 infects respiratory epithelial cells via its cellular receptor angiotensin-converting enzyme 2, causing a viral pneumonia with
pronounced inflammation resulting in significant damage to the lungs and other organ systems, including the kidneys, though symptoms
and disease severity are quite variable depending on the intensity of exposure and presence of underlying conditions that may affect the immune
response. The resulting disease, coronavirus disease 2019 (COVID-19), can cause multi-organ system dysfunction in patients requiring hospitalisation and intensive care treatment. Serious infections like COVID-19 often negatively affect nutritional status, and the resulting nutritional
deficiencies may increase disease severity and impair recovery. One example is the viral infection measles, where associated vitamin A
(VA) deficiency increases disease severity and appropriately timed 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 minimise risks from secondary infections. Second, VA plays a unique role in the respiratory tract, minimising damaging
inflammation, 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
minimises adverse effects of some COVID-19 therapies. Evaluating interactions of SARS-CoV2 infection with VA metabolism may thus provide
improved COVID-19 therapy.
Key words: SARS-CoV2: COVID-19: Vitamin A: Retinoic acid: Immunity: Angiotensin-converting enzyme 2 (ACE2):
The Coronaviridae family of single-stranded RNA viruses
includes four genera: alpha-, beta-, gamma- and deltacoronavirus(1). Seven coronaviruses are known to infect
humans. Two (229E and NL63) from the alpha genus and
two (OC43 and HKU-1) from the beta genus cause mild upper
respiratory tract infections and symptoms of the common
cold. The remaining three human coronaviruses are also in
the beta genus but cause severe lower respiratory tract infections, respiratory failure and death. These viruses are MERSCoV, which causes the Middle East respiratory syndrome;
SARS-CoV1, which causes severe acute respiratory syndrome,
and SARS-CoV2, which is causing the current pandemic of
coronavirus disease 2019 (COVID-19) (1,2). SARS-CoV2
spreads readily from person-to-person due to the long incubation period of 2–14 d following infection(3) and, according to
data available to the WHO, has infected 75 million people and
caused 1·7 million deaths worldwide between December 2019
and December 2020(4).
SARS-CoV2 infection causes..
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