Vitamin D: A crucial ally in the fight against COVID-19?

While a vaccine may not be the secret to ending to our ongoing national nightmare, vitamin D3 just might be.

We’ve talked about this before—more than once, in fact. But there’s another new study to support the role of this critical nutrient in the fight against COVID-19. And it shows that an ample supply of vitamin D does more than just prevent severe illness…

It could keep you from catching COVID-19 in the first place.

Riskier than lung disease

A team of Israeli researchers looked at data from just over 780 COVID-19 positive patients and 7,025 COVID-19 negative patients. And they found that low levels of vitamin D were an independent risk factor for both infection and hospitalization.

But the main finding was the significant link between low vitamin D and infection risk. Because it held even after researchers adjusted for a whole host of other factors—including age, gender, and chronic disorders.

That’s important, because this study identified two age groups of peak positivity—around 25 years old and 50 years old. (Both are potentially due to social gathering habits. And it also goes to show you that the young are by no means immune to the virus.)

Also notable? Researchers found that chronic medical conditions—like dementia, heart disease, and lung disease—weren’t linked with higher rates of infection. (That’s despite being considered exceptionally risky in other studies.)

Again, this could boil down to social habits—in this population, the high-risk subjects might have been more vigilant about staying home and away from other people.

But nevertheless, when low vitamin D emerges as a greater infection risk factor than any one of these common chronic illnesses, it makes you wonder whether widespread rates of deficiency is another key factor fueling this pandemic.

Back to the basics

I’ve described the vital role that vitamin D plays in modulating the immune system—and mitigating one of the main processes behind severe COVID-19 illness—in our previous discussions on the subject.

But with another summer soon behind us—and a new cold and flu season full of darker, shorter days ahead—let’s revisit the basics of smart supplementation. Starting with the fact that there’s a big difference between “adequate” levels and “optimal” levels of vitamin D.

Most mainstream doctors consider a level of 30 ng/mL to be “adequate.” But that’s the bare minimum your body needs to keep functioning. Vitamin D’s best benefits don’t really kick in until levels reach 80 to 100 ng/mL. That’s optimal.

That’s why I recommend at least 2,000 to 5,000 IU of D3 daily. But most people will likely need more. (I personally take 10,000 IU daily myself. And as long as your blood levels are screened regularly, that’s a perfectly safe—and in many cases, necessary—dosage to get you where you need to be.)

So, start supplementing—starting today. Especially with this year’s cold and flu season right around the corner, which promises to be like no other before it. And for additional ways to keep your immune system firing on all cylinders, check out my Complete Guide to Year-Round Immunity.


“Low plasma 25(OH) vitamin D level associated with increased risk of COVID-19 infection.” Science Daily, 07/27/2020. (