Can Supplements Help Protect You from COVID-19?

In addition to masking, social distancing, and hand sanitizing, there are two cheap supplements people can take that might provide an extra edge against COVID-19 while awaiting vaccination and herd immunity.

Vitamin D

An article in The Journal of Clinical Endocrinology & Metabolism by Hernandez et al reported that 82% of people admitted to a Spanish hospital for COVID-19 infection had vitamin D deficiency–in “sunny Spain” of all places! This was almost twice the deficiency rate (47%) of a population control group without COVID-19. Vitamin D deficiency might therefore increase vulnerability to severe infection that requires hospitalization. A Belgian hospital reported that 59% of COVID-19 admissions were vitamin D deficient on admission and that those with vitamin D deficiency were three times as likely to die.

Although association does not prove causation, the vitamin D hypothesis may make sense because 1) vitamin D is known to be necessary for immune function; 2) it could partially explain the greater ferociousness of the virus in the winter, when there is less sun exposure to make vitamin D in the skin; and 3) it might be one of many reasons for the greater impact of the virus in people of color, because dark-skinned people are more vulnerable to vitamin D deficiency.

During the seasonal dark days, I recommend 1,000 to 2,000 IU per day of vitamin D with some fat-containing food to aid absorption of this fat-soluble vitamin. Some vitamin D is also advisable in spring and summer. D3 (the kind made by sun-exposed skin) is a little better than D2.

Essential Fatty Acids

The second area for possible extra protection is in the regulation of the inflammatory reaction. Many COVID-19 deaths apparently result from a cytokine storm from an unbridled inflammatory reaction. Some inflammation is necessary to fight infection, but it is possible to have too much of a good thing.

Essential fatty acids are important in supplying the building blocks for eicosanoids, metabolites such as prostaglandins, which help regulate inflammation to the right level. The omega-6 fatty acid arachidonic acid is the precursor for the series 2 pro-inflammatory eicosanoids, and there is plenty (maybe too much) of this in the average American diet. The omega-3 fatty acid eicosapentaenoic acid (EPA) is the precursor for the anti-inflammatory series 3 eicosanoids that keep inflammation in balance. The average American diet is short on EPA unless one eats oily wild ocean fish at least three times a week. Fish oil and other marine oils have EPA (along with some docosahexaenoic acid, DHA, which can be back-converted to EPA).

Although theoretically alpha-linolenic acid in seed oils could be converted to EPA, there are two reasons to be cautious about depending on this: 1) some people genetically lack the necessary desaturase/elongase enzymes for the conversion, and 2) the overabundant omega-6 fatty acids in the average modern diet compete for those enzymes and may “crowd out” alpha-linolenic acid’s access to them. So the safest course is to take EPA directly.

I recommend at least a gram a day of fish oil or other marine oil, but I would not go over two grams, at least not for very long. Make sure it’s refined to eliminate mercury or has USP on the label, indicating scrutiny by the U.S. Pharmacopeia.

An additional consideration is a multivitamin/mineral supplement for the stress of the pandemic. Research supports the value of B vitamins for enhancing resilience to stress and additional benefit from a broad-spectrum micronutrient formulation with all the known vitamins and essential minerals. This is especially important for the 90% of Americans who do not eat enough vegetables and fruit. The label should list at least 20 vitamins and minerals. Note that most such formulations have considerably less than 1,000 IUs of vitamin D, so you would need to take extra vitamin D with it in the winter.

It is important to emphasize that these do not replace masking, social distancing, hand sanitizing, and vaccination. The nutrient recommendations listed above will not make you invincible. But 1,000 to 2,000 IU of vitamin D and a gram of fish oil per day are easy, cheap, sensible, and might give a little extra protection and reassurance.