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Vitamin status in COVID-19


Although vitamin D deficiency has been noted as a common risk factor for COVID-19 infection and mortality, and vitamin C has been proposed as a potential therapy for COVID-19, the general vitamin status of COVID patients hasn’t been thoroughly investigated.

The study

This review details how vitamins D, C, B, and A could be related to COVID-19, in terms of how they may contribute to ordinary biological function and how deficiency may increase the risk of infection or severity of disease.

The results

Although randomized controlled trials have not shown that vitamin D reduces disease severity, there is a notable correlation between vitamin D levels and COVID infection and poor outcomes. It’s possible that vitamin D could reduce risk of infections and death by maintaining cell junctions, improving innate immunity, acting as an antimicrobial, and modifying gene expression. High-dose vitamin C has been reported to improve moderate-to-severe COVID-19 infection in China, which could be due to its ability to improve the integrity of lung tissue and improve fluid clearance in the lungs. Although this specific mechanism hasn’t been demonstrated in COVID-19, it has been shown to have this effect in other instances of acute respiratory distress. Although the evidence for B vitamins is mostly hypothetical, they could feasibly have an effect by stimulating the immune system. Similarly, only hypothetical evidence exists for vitamin A, but it could have an effect by modulating the growth, function, and differentiation of immune cells. There are a number of trials currently in the works to investigate how these vitamins actually affect COVID-19 risk and outcome.


This study was published in September 2020, and a randomized controlled trial actually came out in October that found vitamin D did reduce COVID-19 severity and time in the intensive care unit.[1]

There are 6 more summaries in the Immunity & Infectious Disease category for December 2020 including ...

  • A systematic review of vitamin D deficiency in the context of COVID-19
  • How does nutritional status correlate with COVID outcome?
  • Predictors of critical illness from COVID-19

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