People with COVID-19 have lower levels of vitamin C.

Micronutrients – vitamins and minerals – facilitate the body’s immune responses to viral infections. Poor micronutrient status diminishes these responses and may contribute to the emergence of more virulent strains of viruses. Findings from a recent study suggest that people with COVID-19 have poor vitamin C status.

Vitamin C is a water-soluble vitamin that plays important roles in immune function. For example, immune cells release large quantities of reactive oxygen species, often incurring damage. To protect themselves from this damage, immune cells accumulate large quantities of vitamin C, which serves as an antioxidant within the cells. Immune cells also release interferons, a class of proteins that participate in antiviral activity. Some evidence indicates that vitamin C promotes interferon production.

The investigators collected 82 blood samples from patients with COVID-19 and healthy people. They categorized the patients according to the severity of their disease (mild, severe, critical, fatal) and measured the concentrations of various micronutrients (vitamins A, C, D, and E) in their blood samples.

They found that the patients with COVID-19 had markedly lower vitamin C concentrations than the healthy people. Patients with the lowest concentrations tended to have longer hospital stays and were more likely to die than those with higher concentrations. The investigators did not observe similar trends for any of the other micronutrients measured. However, other research has shown that poor vitamin D status increases the risk of COVID-19 infection and severe outcomes.

These findings demonstrate that people with COVID-19 have poor vitamin C status, which may influence the severity of their disease. Learn more about the health benefits of vitamin C in our overview article.

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