Higher levels of vitamin D are associated with a reduced risk of COVID-19, influenza, and other respiratory infections. If you do get sick, having adequate vitamin D levels may reduce your symptoms and improve your outcome.

Until we have a vaccine for COVID-19, vitamin D supplementation represents a safe, simple risk-reduction strategy.

Until we have a vaccine for COVID-19, vitamin D supplementation represents a safe, simple risk-reduction strategy.
Photo by Martin Sanchez on unsplash.com

The world awaits a vaccine for SARS-Cov-2, the virus that causes COVID-19. In the meantime, what can we do to protect ourselves? While social distancing and frequent hand-washing remain the most effective strategy for COVID-19 risk reduction, scientific research has suggested an important role for vitamin D supplementation. Surprised? While it may not sound as sexy as a powerful, blockbuster drug, vitamin D has an impressive track record in fighting influenza and other respiratory infections.

Evidence suggests that vitamin D could have a major impact on the prevention and management of COVID-19.

Evidence suggests that vitamin D could have a major impact on the prevention and management of COVID-19.
Photo by Michele Blackwell on unsplash.com

Vitamin D is Effective in Fighting Upper Respiratory Diseases

Vitamin D is known to be effective against upper respiratory diseases.  In a review of 25 studies, vitamin D supplementation was found to protect against acute respiratory tract infections. Patients, with the lowest vitamin D levels experienced the most benefit.

Vitamin D can lower the risk of infection through several mechanisms. 

  • by reducing pro-inflammatory compounds in the lining of the lungs, in turn fighting pneumonia
  • by increasing concentration of anti-inflammatory compounds

What Evidence is There That Vitamin D Will Be Effective Against COVID 19?

Evidence in support of vitamin D for reducing the risk of COVID-19 includes:

  • COVID 19 outbreaks occurred in winter, a time when vitamin D (25-hydroxyvitamin D (25(OH)D) concentrations are lowest
  • the number of cases in the Southern hemisphere near the end of summer is low
  • vitamin D deficiency has been found to contribute to acute respiratory distress syndrome
  • case-fatality rates increase with age and with chronic disease comorbidity, both of which are associated with lower vitamin D (25(OH)D) concentration

To reduce the risk of infection, it is recommended that people more susceptible to influenza and/or COVID-19 consider taking:

  • 10,000 IU of vitamin D3  each day for a few weeks to rapidly increase 25(OH)D concentrations
  • A maintenance dose of 5000 IU per day thereafter, with the goal being to raise 25(OH)D concentrations above 40–60 ng/mL (100–150 nmol/L).

For the treatment of people who become infected with COVID-19, higher doses of vitamin D3 might be useful. Randomized controlled trials and large population studies should be conducted to evaluate these recommendations. 

In 2011, The Endocrine Society issued a report arguing in favor of a much higher recommended minimum blood level of vitamin D. At that time, their experts concluded:

“Based on all the evidence, at a minimum, we recommend vitamin D levels of 30 ng/mL, and because of the vagaries of some of the assays, to guarantee sufficiency, we recommend between 40 and 60 ng/mL for both children and adults.”

 Sunshine is not a reliable source of vitamin D and may not produce sufficient levels to protect against upper respiratory tract infections and COVID-19.

 Sunshine is not a reliable source of vitamin D and may not produce sufficient levels to protect against upper respiratory tract infections and COVID-19. 
Photo by Felipe Archer on unsplash.com

The Bottom Line

Dozens of studies over the years have demonstrated the safety and effectiveness of vitamin D in lowering the risk of many chronic and degenerative diseases. Most Americans are deficient in vitamin D. There are few reliable dietary sources and the majority of us don’t get enough of the type of sun exposure needed for our bodies to produce adequate levels of vitamin D. Additionally, the levels of vitamin D required for calcium metabolism and bone health are lower than the amount needed for prevention and management of upper respiratory tract infection, such as influenza and COVID-19.

Evidence continues to build that vitamin D supplementation—at the right dose—can be effective in fighting COVID-19. We should follow the recommendations of those scientists who have been conducting this research, as our public health officials, sadly, continue to recommend a woefully inadequate dose of vitamin D.