Supplements that contain higher than federally recommended levels of vitamins C and D may be a safe, effective, and low-cost way of helping your immune system fight coronavirus disease 2019 (COVID-19), according to a study published in Nutrients.

The COVID-19 pandemic has caused more than 800,000 deaths with over 23.3 million cases reported worldwide, according to the World Health Organization. Acute respiratory tract infections kill more than 2.5 million people every year, according to the study.

Vitamins C and D, zinc, and omega-3 fatty acids are critical for immune function. Not eating enough of these essential nutrients can affect resistance to infection, increase disease severity, and burdens associated with the disease.

Researchers from Oregon State University (OSU) are urging the use of a daily multivitamin, but also vitamin C and vitamin D supplements much higher than federally recommended guidelines. The study authors recommended 200 milligrams or more of vitamin C and 2000 international units of vitamin D.

The federally recommended level of vitamin C is 75 milligrams for men and 50 milligrams for women. For vitamin D, the federally recommended levels are 400 to 800 international units depending on age, according to the study.

The study authors noted that the issue with these nutrients is that people simply aren’t eating enough in their diet. Multivitamins and supplements can help fill the gaps. Public health practices such as social distancing, hygiene, and vaccines are important in the fight against COVID-19; however, the study authors said that these strategies should be used to compliment a focus on nutrition and the immune system.

"A number of standard public health practices have been developed to help limit the spread and impact of respiratory viruses: regular hand washing, avoiding those showing symptoms of infection, and covering coughs…And for certain viruses like influenza, there are annual vaccination campaigns," Adrian Gombart, PhD, professor of biochemistry and biophysics in the OSU College of Science and a principal investigator at the Linus Pauling Institute, said in the press release.

Vaccines, when available can be highly effective, the study authors said; however, an emphasis on nutrition and the immune system is still needed for an effective disease response.

Reference
Dietary supplements an important weapon for fighting off COVID-19 (Press release) Corvallis, Ore. April 23, 2020, EurekAlert!, accessed August 24, 2020