Dietary supplements “crucial in fighting off COVID-19,” says study

24 Apr 2020 --- Micronutrient-rich supplements are a safe, effective and inexpensive means of strengthening resistance to infections and protecting the body from respiratory diseases, including COVID-19, according to a new study review from the Oregon State University (OSU), US. The research team warrants supplementation above the Recommended Dietary Allowance (RDA), but within recommended upper safety limits, for specific nutrients, such as vitamins C and D. The study also appeals for public health officials to delineate nutritional strategies in public health recommendations, with frequent hand washing and social distancing at the forefront, to help prevent the spread of infections further.

“The situation with COVID-19 and the number of people dying from other respiratory infections make it clear that we are not doing enough. We strongly encourage public health officials to include nutritional strategies in their arsenal,” says principal investigator Adrian Gombart, Professor of Biochemistry and Biophysics in the OSU College of Science.

Such additional strategies to support the immune system are currently greatly in demand, considering a vaccine against COVID-19 could still be over a year away.

“Around the world, acute respiratory tract infections kill more than 2.5 million people every year. Meanwhile, there’s a wealth of data that shows the role that good nutrition plays in supporting the immune system. As a society, we need to be doing a better job of getting that message across along with the other important, more common messages,” continues Gombart.

"Inadequate intake of key nutrients are widespread, leading to a decrease in resistance to infections and as a consequence an increase in disease burden," the study abstract reads. Building blocks for boosted immunity?
Specific vitamins, minerals and fatty acids have key jobs to play in helping your immune system, states Gombart. In particular, vitamin C, vitamin D, zinc, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are critical for immune function.

According to the study review, increased, widespread vitamin C supplementation could help strengthen several aspects of immunity, including epithelial barrier function, growth and function of both innate and adaptive immune cells, white blood cell migration to sites of infection, phagocytosis and microbial killing and antibody production. Last month, some US hospitals started to administer large doses of intravenous vitamin C to some COVID-19 patients. Meanwhile, a clinical trial with vitamin C is underway in China, examining to what extent coronavirus symptoms can be treated. 

Moreover, vitamin D metabolites appear to regulate the production of specific antimicrobial proteins that directly kill pathogens and thus are likely to help reduce infection, including in the lungs. NutritionInsight previously reported that some researchers were already calling for “urgent supplementation” in vulnerable groups in light of recent studies. 

The review also views zinc as necessary for developing cells in both the innate and adaptive immune systems. Critically, zinc deficiency results in the impaired formation, activation and maturation of lymphocytes, disturbs the intercellular communication via cytokines and weakens the innate host defense. The review also suggests an important role for EPA and DHA in ameliorating inflammation and lung injury.

Equipped with these findings, the researchers are urging not only a daily multivitamin, but also doses of 200 mg or more of vitamin C, which is significantly higher than the RDA of 75 mg for men and 50 for women. Likewise, they call for 2,000 IU of vitamin D, rather than the 400 to 800 recommended, depending on age.

“The problem is that people simply aren't eating enough of these nutrients. This could destroy your resistance to infections. Consequently, we will see an increase in disease and all of the extra burdens that go along with that increase,” Gombart affirms.

There’s no magic pill
Wary of the “clever marketing ploys” seen in some instances within the supplement industry, Registered Dietician Aisling Pigott from the British Dietetic Association (BDA) tells NutritionInsight that many supplements will contain large doses of micronutrients. “We don’t necessarily need large doses of these nutrients. An excess of one nutrient, for example, magnesium, may lead to reduced absorption of another, such as zinc, creating more issues than there were to begin.”

She also highlights that buying “expensive and glamorous supplements” does not exempt people from paying attention to healthy and balanced dietary patterns. Besides getting enough healthy sun exposure – giving vitamin D its nickname “the sunshine vitamin” – the BDA recommends eating plenty of vitamin D-rich foods, including oily fish, egg yolks, meat and milk. Additionally, margarine, some breakfast cereals and some yogurts are also fortified with vitamin D.

Edited by Anni Schleicher