Doctors and scientists say to supplement vitamin D for COVID-19. Why isn’t anyone listening?
By: Michael D. Appleby
Tags: Coronavirus, Influenza, Covid 19, Vitamin D, Medicine

It’s cheap, easy, and safe. It’s already recommended that everyone take it in the winter. The science is plausible. What more do you need?

The pandemic has brought with it a huge wealth of novel data.

From this there has emerged a very good case that vitamin D reduces the severity of COVID-19 and other enveloped respiratory viruses, like influenza.

Moved by such evidence, a Dec. 7th open letter signed by scientists, doctors, & authorities was circulated calling for increased Vitamin D use to combat COVID-19. #VitaminDforAll

This post is my explanation of why the connection is credible.

Background Explanation

90% of our vitamin D is produced from sunlight reacting with our skin. This means that the sunshine vitamin waxes and wanes in step with the seasons, and so it can effectively function as a biochemical calendar that an animal’s cells can use to ‘know’ what season it is.

This is important because, in the winter, food is more likely to become unavailable. Our bodies curtail many of the more costly cellular activities until spring. This includes activities like vigorously growing and renewing bones or maintaining a costly, highly-active immune system 24/7, even when no invader has been detected.

Other coronaviruses and influenza are known to strike seasonally, and they reliably choose the seasons when sunlight is scarce. In temperate regions this means fall and winter, in tropical regions this means the rainy season. COVID-19 case numbers around the world fit into exactly this usual seasonal pattern.

Of course there are other factors that also contribute to such seasonality. For example, it is known that enveloped viruses survive longer outside in the cold. They are also better at infecting us when our mucus has dried out from the dry indoor air that our furnaces produce in the winter. However, these factors can’t easily explain the increase of influenza cases seen in the warm and humid rainy season of tropical climates.

We have long known that summer inoculations of a live attenuated influenza virus, such as when we give a nasal vaccine, produce reduced symptoms(aka side effects) and provoke a markedly reduced immune response. The virus is directly administered here, so this cannot be waved away as due to some seasonal difference in external conditions. Something is different about the conditions inside our bodies.

This suggests that wild flu has reduced disease severity in the summer, perhaps generally ranging from asymptomatic to a cold. This would explain how a typical regional strain of influenza B can seemingly completely vanish each spring, only for the exact same strain to return with the falling leaves. We are the only host for influenza B strains, so they are better-adapted to us and avoid locally dying out in the summer.

Recent Evidence

There just isn’t enough vitamin D present in even well-balanced diets to support us through winter. The usual dietary and solar form of vitamin D, D3 is rapidly sequestered and stored in the fat throughout our body, where it sits inert. At usual intakes it takes around a week for it to be activated by the liver into calcifediol. This is too long to expect it to help treat an already hospitalized patient, and several studies have found the D3 form to be ineffective as a treatment for COVID-19.

However, there has been one randomized controlled trial where they investigated treating with rapidly-active calcifediol instead.

The results were stunning. 13 out of 26 controls progressed to the ICU, where 2 died. Only 1 of the 50 treated progressed to the ICU. All survived.

A pair of scholars out of MIT have persuasively argued that these results constitute very unusually significant evidence for a trial of its design and size.

Follow up trials are already in progress, but why should we wait?

This result is well corroborated by other lines of evidence. For example, many studies have found that severe cases of COVID-19 are strongly associated with an increased rate of vitamin D deficiency. A meta-analysis of 27 such articles found that “severe cases of COVID-19 present 64% more vitamin D deficiency compared with mild cases.” Furthermore it suggests that full-on deficiency is not required. Increased mortality and hospitalization were significantly correlated with even mere insufficiency.

The pandemic in sun-drenched Sub-Saharan Africa has been mild enough that the WHO estimates that over 80% of cases have been asymptomatic. There have been ~40,000 deaths there in a population of 1.1 billion. That’s only 36 deaths per million, fully 6 times lower than the global average of 220.

However, the population of Africa is very young, with a median age of 20. Even still, the number is so good that even when we exclude everyone under 20 it comes out to 72 deaths per million, still 3x lower. Yet in the US, black people are about 4x more likely to be hospitalized and nearly 3x more likely to die.

What could be so different that might account for something like a 9-fold difference?

It’s not lack of exposure. Antibody surveys throughout Africa suggest that the proportion of Africans that have been exposed is similar to that of Americans. COVID-19 really seems to be much less severe there. The discrepancy is simply too large to be easily chalked up to age or unreliable record keeping.

Anyways, these were just a couple observations that I personally find particularly compelling. There’s a lot more evidence out there.

Conclusion

Health authorities are aware but are unlikely to issue any conclusive special recommendations until a connection has been absolutely proven. But you and I certainly don’t need to wait for a large, flawlessly-executed randomized controlled trial just to start doing supplementing something we already should have been taking all along!

I urge you to do the prudent thing this year and pick up a ~$15 bottle of vitamin D. Hospitals are at capacity, and rolling out the vaccine is going to take time.

Daily doses of 2k to 4k IU daily are safe and would likely be effective. Alternatively, Vitamin D can also be taken weekly(or even monthly). You may find it easier to remember to take a dose of 7k to 30k once a week.

Vitamin D is stored up over months. In order to see immediate benefit, you will have to make up for lost time. In the dead of winter, a one-time only 100k IU loading dose is a conservative option as it is equivalent to less than a month of 4k doses. It should be taken with a fatty meal. Going somewhat above this might provide additional benefit, but then this starts to become medical advice and interactions will begin to matter. The Mayo Clinic’s List of Interactions

So consider sending an email to your doctor asking how best to immediately jump start to a healthy springtime vitamin D level.

In any case don’t go radically overboard. Springtime is when influenza goes away; there is unlikely to be much additional benefit in raising vitamin D levels too far beyond that.

Please share this. So far this message hasn’t been able to shine through the haze of all the usual vitamin and medical news. Awareness will continue to remain low unless people help boost discussion.

Hospitals are crowded; right now every additional free bed helps.

There is at least a modest chance that vitamin D helps and no one thinks that it hurts.

Why would we need more than that just to do something cheap and easy that we are already supposed to be doing anyway?

Thank you for your time.