Vitamin D strikes out again

The idea that vitamin D supplementation is a cheap and safe way to avoid infection has gotten considerable attention during the pandemic. A newly published randomized controlled trial found that boosting vitamin D levels in deficient people was not protective against Covid-19 or other acute respiratory infections.

This latest study has appeared as a preprint, meaning it has not undergone peer review. Of interest (to me, anyway) is that under declared potential conflicts of interest, it’s noted that one study organizer has previously gotten funding from makers of vitamin D supplements.

One idea under consideration is that deficient vitamin D levels may correlate with overall poor health status and thus increased susceptibility to infections, but that vitamin D itself is not all that important.

We use “EmergenC” (or off brand knockoffs) with zinc and vitamin C+D, when it seems one of us is coming down with a cold/flu. I’m pretty comfortable with the fact its more placebo than anything else.

My working model is that vitamin D is an easily measurable proxy for hard-to-quantify generally healthy lifestyle that is correlated with getting a decent amount of natural sunlight.

Taking vitamin D pills will not help. Very possibly specifically spending time in the sun will not help either, since it’s not necessarily the sunlight that’s the important thing either, just another confounder.

Vitamin D does not protect one from catching things. Neither do vaccines. But vaccines prepare your immune system to specifically quickly kill a specific infection, often before you even notice it tried to invade. Adequate vitamin D levels among many other health benefits, help your immune system be in good shape to deal better with various infections than if you were lacking in vitamin D. A good vaccine can be effective even in a person with lax health levels in general. Vitamin D is not so strongly targeted in effect and poor general health will negate it’s good effect on the immune system.
Vitamin D is just one of many things that help you have a stronger response to get through infections.

Vaccines obviously do protect you from “catching things” - even Covid-19 vaccines, which work especially well to prevent serious illness and death. If you’re going to define infectious disease prevention as “not letting germs into my body” there will be precious little that works aside from submerging in bleach and the like, which is not pleasant.

Vitamin D, vitamin C, proper diet etc. are important in maintaining an optimally functioning immune system. That doesn’t mean that vitamin supplementation and “superfoods” will necessarily have significant health benefits. There’s evidence that vitamin D has been overhyped in recent years and can be overdone, leading to deleterious effects.

I’d be far more concerned with having optimal vaccination status re Covid-19 than with taking vitamin D supplements.

Vaccines prepare your immune system to react to something when it enters your body. That something may or may not be successful to some extent at infecting. But your vaccine primed immune system will very effectively kill it. As to the covid vaccines. It is now accepted that they do not prevent infection. But they do prime the immune system to better attack and lessen severity.
I agree that there is lots of unsupported hype of many vitamins or foods being wonders for health.
The body needs the proper balance of things. Lots of one thing will not make you some super healthy being. Too much of a thing is usually bad.
Due to our modern lifestyles and being in certain geographical locations or economic state can lead to too little or too much of things. Vitamin D deficiency is just one thing that can be an issue due to one or more of these issues.

That’s untrue.

“All three COVID-19 vaccines authorized in the U.S. were designed to prevent severe infection, hospitalization and death. But experts and public health officials say the shots also protect people from contracting and spreading the virus.”

“What we know is that individuals who are vaccinated are much less likely to be infected therefore much less likely to spread the virus,” Dr. Amesh Adalja, a senior scholar at the Johns Hopkins Center for Health."

The same holds true for Omicron and subvariants, though such protection lessens over time, hence the need for boosters.

Right. I think some people may inadvertently confuse “prevent infection” with “prevent infectious agents from entering the body in the first place”. To be fair, infection control protocols often speak of measures like handwashing and covering wounds as helping “prevent infection”, which reinforces that confusion.

I think what Kedikat is trying to get at is the difference between “sterilizing immunity”, which prevents the infectious agent from reproducing in the cells at all after it enters the body (and which is more of a theoretical ideal than a practical goal even for the most effective vaccines, AFAICT) and “functional immunity”, which “merely” controls the infection enough that you don’t get sick.

As far as I have seen the mRNA vaccines were specifically designed with the spike protein as a target. They actually stimulate the production of the spike protein by your own cells. Which makes your immune system create defenses to that protein. So the vaccine has shown good effect to protect us from those very bad spike proteins, which is a very good effect. But they do not particularly defeat the replication of the virus that is producing that spike protein in particular. The overall virus is a more complex target. So you can still suffer quite a large effect of being infected with the virus as you can with a flu or similar virus. But not suffer the more damaging effects of the spike protein.

I am definitely not anti vaccine. Have gladly got more than the average array of vaccines due to world travel for my work. Vaccines are in the top great 3 things of medical science. The mRNA vaccines are a new application. They targeted a certain aspect of the Covid virus and seemed to have succeeded in that.

I thought that the vaccine reduces the amount of time that a person is infected, so while they don’t reduce the spread from an already-infected person to another, they do reduce the overall spread.

That may be so. That spike protein is a very nasty thing. Maybe if you did not have the vaccine your system would have a harder time fighting the infection. The spike protein itself causing immune battles as well as the whole virus being battled. So a longer time being infected and possibly spreading.
I have not been able to nail down information on aspects of the spike protein as a free agent in the system and being a target on the virus itself. It seems that either way targeting it does not kill the virus. But it does save one from the nasty effects of it, once it is in the system.

Yes, taking more Vit D or whatever won’t help. But a deficiency is another matter entirely, and a Vit D deficiency is one of the more common ones in the USA. Being sickly and having a lowered health due to deficiencies will make anything you do catch worse.

As the study concluded : Having said that, it’s clear that (at least in this population) vitamin D deficiency is widespread, and supplementation may be appropriate for individuals anyway.

. We observed a positive association between vitamin D deficiency and the severity of the disease.

Our study demonstrates an association between VitD deficiency and severity/mortality of COVID-19, highlighting the need for interventional studies on VitD supplementation in SARS-CoV-2 infected individuals

But yeah, taking a large dose of Vit D will not prevent Covid. It could make you sick, even.

I’m a ghost-white person who religiously avoids the sun and works indoors at a desk all day. I seemed like a good candidate for vitamin D deficiency, so I take a supplement. In case I get Covid, at least I’m topped up in that regard and have a better chance of fighting it off.

Walensky has not helped the cause of science-based medicine by repeatedly mischaracterizing consensus knowledge about Covid-19 and countermeasures, to the point where it was reported she was getting media consultant advice on “messaging”.

Walensky’s remarks have also been twisted by opponents.

As previously noted, we have good evidence that Covid vaccines do limit transmission even though they don’t prevent it in all cases.


Then you’d presumably agree that it’s desirable to emphasize factual information about vaccination, accurately describing the CDC’s position, and not suggesting that vaccination is no more effective than prophylactic vitamin D in preventing infection.

There are parts of Canada that do not frequently see the sun in the winter. But they add it to some dairy products. People selling vitamins quote strangely large percentages of people are deficient in things like magnesium or various vitamins. I’d like to know the real numbers.

It’s a cheap intervention, but I doubt it is very helpful for Covid for most people. There is a long list of vitamins being found of little benefit. I remember the HOPE study showing vitamin E was not helpful in cardiovascular outcomes. I do sometimes take niacin and fish oil. The evidence is not great, but some of the studies are also not great.

Well, here’s the section on micronutrients in the 2012 CDC Second Nutrition Report. Lotsa graphs about all sorts of micronutrient levels in the US population.

Sure. You can make graphs showing the distribution, normalize it, figure out what the cutoffs are at 5% and 95% and others. This helps some. But the recommendations about how much is actually needed vary a lot from place to place.

Here’s a recent study funding a correlation between low vitamin d and the likelihood of developing long covid:

Here’s a more readable summary