The findings from this study about supplements and Covid-19 were so meta. A meta-analysis recently published in the journal Clinical Nutrition ESPEN found no statistically significant associations between vitamin C, vitamin D, or zinc supplementation and decreased Covid-19 mortality. However, it did find that those who had taken vitamin D supplements were less likely to get intubated and had on average shorter hospital lengths of stay than those who had received standard Covid-19 care alone. But before you jump all over these findings like a seagull on a hot dog, keep in mind what a meta-analysis is.
A meta-analysis is not an analysis conducted by Meta, the company formerly known as Facebook. And it’s also not an analysis of a soft cheese made from whole sheep’s milk. That would be a feta-analysis. Instead, a meta-analysis entails first collecting all of the available studies that measure the effect of a particular intervention…in this case taking vitamin C, vitamin D, or zinc supplements.
For this meta-analysis, the research team from the University of Toledo (Azizullah Beran, Mohammed Mhanna, Omar Srour, Hazem Ayesh, Jamie M. Stewart, Majdal Hjouj, Waleed Khokher, Asmaa S. Mhanna, Dana Ghazaleh, Yasmin Khader, Wasef Sayeh, and Ragheb Assaly) found a total of 26 studies, including 10 randomized controlled trials and 16 observational studies, that had a total of 5,633 patients with Covid-19. The team pooled together these studies and then used statistical techniques to merge and synthesize the results from each of these studies. These techniques then allowed the team to quantify the overall effects of the supplements.
Collectively, the nine studies that evaluated the use vitamin C supplements, the five studies that evaluated the use of zinc supplements, and the 14 studies that evaluated the use Vitamin D supplements didn’t find any statistically significant effects on Covid-19 mortality. However, the Vitamin D studies, which encompassed a total of 927 patients getting vitamin D supplements compared to 2570 patients just getting standard care, did show vitamin D supplementation to be associated with a 45% lower rate of getting intubated and on average a 1.26-day shorter hospital length of stay.
This certainly wasn’t the first study to find a possible relationship between vitamin D and Covid-19. I covered for Forbes some of these studies back in May 2020. Then, a meta-analysis published in November 2020 in the journal Critical Reviews in Food Science and Nutrition found vitamin D deficiency to be associated with more severe Covid-19. And a study recently published in PLOS ONE revealed that among 1176 patients hospitalized with Covid-19 in Israel, those with vitamin D deficiency were 14 times more likely to have severe or critical Covid-19 than those with normal levels of vitamin D.
Here’s a Q&A from the University of Chicago Medical Center, otherwise known as UChicago Medicine, about vitamin D and Covid-19 that was posted back in May 2021:
As you can see, vitamin D may play a role in regulating various immune system responses. It may help the cells that assist in identifying an invader and also prevent the response from getting out of hand. Such functions could prove useful in managing Covid-19, since the disease is a combo of direct damage from the virus and your immune system firing off in random directions like a virgin who’s on a real date for the first time.
This doesn’t necessarily mean that you should start pounding vitamin D supplements by the fistful. Meta-analyses have their limitations. They try to pool together different studies that may vary greatly in quality and design. This can be a coat-necktie-short pants situation or even a coat-tie-thong situation where things don’t really match, weakening the validity of any conclusions. In fact, many of the existing vitamin D studies have numerous holes like your underwear may have when you rub your bottom with a cheese grater. Even the better-constructed studies can only show associations and not cause-and-effect. So take any conclusions from this meta-analysis with a hot dog full of salt. More studies are needed to more definitively establish whether there are any possible links between Vitamin D and protection against bad Covid-19 outcomes.
At this point, if you are indeed deficient in vitamin D, it would make sense to take vitamin D supplements. This could have additional health benefits beyond Covid-19-related ones. After all, vitamin D has been associated with good things like stronger bones. In general, taking vitamin D supplements can’t hurt, assuming that you don’t overdo it and get the supplements from a legitimate source. If the person selling supplements to you also says something about “The Deep State” or tries to tell you that vaccines make keys stick to your forehead, you may want to try a different source. Beware of supplements that may include extra unnecessary ingredients or be adulterated in any other way. Note that I am saying adulterated here and not adultery, although adultery supplements would be bad too. If your vitamin D pill is giving you an erection, it’s probably not just vitamin D. Vitamin D alone should not be that exciting.
Also, taking vitamin D is in no way a replacement for getting vaccinated against Covid-19. It’s not going to protect you against Covid-19 in the same way, unless of course you are too busy taking supplements to leave your house.