NEWS

Although we have no data regarding nutritional factors in relation to risk and severity of COVID-19, what are some examples of existing evidence on nutrition and infection that would be important to consider?

Zinc is a component of many enzymes and transcription factors in cells all over the body, and inadequate zinc levels limit the individual's ability to mount an adequate immune response to infections. Multiple meta-analyses and pooled analyses of randomized controlled trials (RCTs) have shown that oral zinc supplementation reduces the incidence rate of acute respiratory infections by 35%, shortens the duration of flu-like symptoms by approximately 2 days, and improves the rate of recovery.

Vitamin C is a cofactor for many enzymes. It enhances the function of many enzymes all over the body by keeping their metal ions in the reduced form. It also acts as an antioxidant, limiting inflammation and tissue damage associated with immune responses. Vitamin C was shown to reduce the duration of stay in the intensive care unit and need for mechanical ventilation among these patients. The dose of vitamin C varied from 1-3 g/day, and dose does not appear to be the main driver of effectiveness. Doses of vitamin C above 2g/day should be avoided outside of medical care.

Magnesium is an essential mineral found mainly in beans, nuts, seeds, whole grains, and green leafy vegetables. Your body needs magnesium for making protein, bone, and DNA and to regulate muscle and nerve function, blood sugar levels, and blood pressure. 

Vitamin D is normally produced in our skin when exposed to sunlight, and in the late winter and spring blood levels of vitamin D tend to be low because of reduced sun exposure. Staying indoors will further reduce blood levels. Although we do not have evidence at this time whether vitamin D supplements will reduce the severity of COVID-19, they might, especially among people with low levels. Because the cost of blood testing is usually more than the cost of supplements, taking supplemental vitamin D would be reasonable for most people to consider.