New study details COVID-19 risk factors—including nutrition

Research out of the prestigious journal Nature shows the enormous impact natural products retailers can have on public health. Here's the lowdown on which supplements and foods to recommend to shoppers.

Todd Runestad, Content Director,, Sr. Supplements Editor

July 9, 2020

6 Min Read
immunity supplements covid19
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A massive study of 17 million British residents, from data collected by the United Kingdom’s National Health Service, identified key factors that can lead to worse outcomes from COVID-19.

Some of these factors are beyond the reach of any individual to change. For instance, patients older than age 80 were 20 times more likely to die from COVID-19 than those in their 50s—and hundreds of times more likely to die than those in their 30s or younger.

Gender also plays a role—men are more likely to die than women.

Poverty and race also figured into negative health outcomes; in particular, Black and South Asian people were found to be at a higher risk.

In terms of race, data from the U.S. Centers of Disease Control and Prevention revealed that Black and Latinx people are infected with the coronavirus at a rate three times higher than whites.

Based on the infection rate per 10,000 people, the most heavily affected are Latinx people, at 73 cases per 10,000. Blacks are 63 cases per 10,000. Whites are only 11 cases per 10,000.

Socioeconomic status may have something to do with that. The CDC data was teased out by the New York Times, which had to sue the CDC with a Freedom of Information Act request to get the data. It showed 43% of Black and Latinx workers are employed in jobs that cannot be done remotely, while the same holds true for only 25% of whites.

Related:Vitamin K levels linked to COVID-19 outcomes

But the British researchers, whose study published July 8 in the prestigious journal Nature was made up of 40% of the British population, identified risk factors that could be changed.

The four primary medical conditions included obesity, diabetes, severe asthma and compromised immune function.

Asthma is a pre-existing condition, but obesity, diabetes and immune health are changeable.

Diabetes and obesity are diet-related, but immune function in particular might be as simple as taking dietary supplements.

A number of nutritional ingredients have already been determined to decrease the duration and severity of upper respiratory tract infections.

Vitamin D

The sunshine vitamin probably stands as the best-studied nutrient as it relates to both immune function and specifically COVID-19 outcomes. A vitamin D deficiency is associated with increased risk of infections in general. The official recommendation is to have blood levels of 20 ng/dl, but that’s based strictly on the vitamin’s effect on bone health. Most integrative physicians will counsel to have levels at least 40 ng/dl, if not north of 60.

One meta-analysis found best outcomes with URTIs among those who supplemented with blood levels to start at a woeful 10 ng/dl or less—truly deficient.

Vitamin D has actually been shown to benefit for a wide range of health states, including immune function. A Harvard School of Public Health review summarized evidence suggesting optimal vitamin D blood levels in relation to bone mineral density, lower-extremity function, dental health as well as the risk of falls, fractures, and colorectal cancer. Benefits begin at 30 ng/ml, preferably between 36-40 ng/ml. Researchers concluded that at least 1,000 IU/day would bring 30 ng/ml to half of the population.

A study published in May 2020 on vitamin D’s effect on immune function said clinical conclusions on exactly how much vitamin D to take and how frequent was still elusive, but did say that deficiencies are clearly bad and regular intake—versus monthly or biannually as some seniors take intravenously—is preferred.

When talking about prevention—supplements cannot claim to prevent, treat or cure any disease, mind you—a study published in May found that patients in Chicago who had blood levels below 20 ng/ml or who did not take supplements were 77% more likely to test positive for COVID-19.

A similar study in Israel found people with vitamin D levels below 30 ng/ml were 45% more likely to test positive and 95% more likely to be hospitalized.

A study of 780 COVID-19 patients in Indonesia found almost 99% of patients who died had vitamin D levels lower than 20 ng/ml. Significantly, of patients with vitamin D levels higher than 30 ng/ml, only 4% died.

So, how much should retailers recommend for shoppers to take?

A study published in April 2020 concluded vitamin D can reduce the risk of respiratory tract infections. Significantly, vitamin D has been found to lower viral replication rates and reduce the concentrations of pro-inflammatory cytokines that injures the lining of the lungs—which is what the COVID respirators are all about. These Belgium researchers recommended 10,000 IU/day vitamin D to rapidly raise vitamin D concentrations in the blood, followed by maintenance doses of 5,000 IU/day. The end goal is to raise blood levels to between 40-60 ng/dl. “For treatment of people who become infected with COVID-19, higher vitamin D3 doses might be useful.”

Another study, published June 7, 2020, recommended people achieve a minimum blood level of 30 ng/ml. The study noted a significant reduction in infections happened with daily vitamin D doses between 800-2,000 IU.

“Much more attention should be paid to the importance of vitamin D status for the development and course of the disease,” wrote researchers. “With respect to COVID-19, a recommendation for primary prevention of vitamin deficiency seems meaningful.”


The sleep-inducing supplement ingredient is also seen as a possible natural adjunct for COVID-19 patients along with vitamin D. In a study published May 15, 2020, researchers noted that death comes via an inflammatory reaction at the lung level. 

Researchers noted vitamin D and melatonin could attenuate the severity of this “pulmonary complication” that leads to so many COVID-19 deaths.

The two nutrients down-regulate the inflammatory response related to the bodily system that regulates blood pressure and fluid balance in the body, called the renin-angiotensin system.

Hypertension, or high blood pressure, is one of the co-existing conditions that has consistently been reported to be more common among critical COVID-19 patients.

Zinc deficiency has also been associated with increased infection risk.

Essential nutrients—and nutrition

A study published in May 2020 investigated the role of nutritional status in affecting COVID-19 patient outcomes. While the researchers noted that no known evidence-based strategy exists to prevent COVID-19, “it is clear that nutritional status plays a significant role in patient outcomes.”

“To maintain a healthy immune system,” the researchers wrote, “special attention must be given to maintaining a healthy diet, lifestyle, exercise regime and minimal stress as much as safely possible at this difficult time.”

Elderly populations in particular, besides being a significant target of COVID-19 deaths, often have nutritional deficiencies of calcium, vitamins C and D, folate and zinc.

“Certainly, there is considerable evidence that the food and nutrients we consume affect how our immune system functions,” wrote researchers. “Maintaining a body weight and composition in line with recommendations for stature and gender is prudent.”

The researchers noted the benefit of the anti-inflammatory Mediterranean Diet, the perils of the highly processed Western diet, and the benefits of fish and fish oils, probiotics, fiber and healthy fruits and vegetables.

Maintaining a healthy diet is vital in this COVID-19 age, especially for vulnerable populations—the elderly, minority groups and those with underlying health conditions like obesity, diabetes, cardiovascular conditions and compromised immune function.

This group with underlying health conditions represents a fairly sizeable chunk of Americans.

Which is to say, natural food retailers should continue preaching to customers the same advice about living with vitality, and probably with a particular emphasis on maintaining healthy immune function. Healthy organic foods and appropriate supplementation are the real “game changers” in this COVID age.

Editor's note: A previous edition of this story mentioned hydroxychloroquinine—a controversial drug that is not sold in natural foods outlets. That section has been deleted.

About the Author(s)

Todd Runestad

Content Director,, Sr. Supplements Editor, Natural Products Insider

I've been writing on nutrition science news since 1997. I'm The content director for NaturalProductsInsidercom and digital magazines. Other incarnations: supplements editor for, Delicious Living and Natural Foods Merchandiser. Former editor-in-chief of Functional Ingredients magazine and still cover raw material innovations and ingredient science.

Connect with me here

My daily vitamin regime includes a morning smoothie with a range of powders including protein, collagen and spirulina; a quality multi, B complex, C with bioflavonoids, >2,000IU vitamin D, E, magnesium, high-selenium yeast, PQQ, choline, alpha-lipoic acid with carnitine, coQ10, fish oil concentrate, probiotics and some adaptogenic herbs. 

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