This article was previously published on June 21, 2020 and has been updated with new information.
Here, I interview three vitamin D experts about the importance of vitamin D for improving immune function and resistance to viral infections, including COVID-19.
Dr. Bruce Hollis, Medical University of South Carolina, has been researching vitamin D since the late 1970s. His research partner at the University of South Carolina School of Medicine was Dr. Carol Wagner, a neonatologist and researcher. on vitamin D since 2000.
Carole Baggerly is the director and founder of the Baggerly Basic Grass Nutrition Research Institute which received our Game Changer Award in 2018. She began her work in the vitamin D field after treatment. breast cancer in 2005.
Vitamin D levels correlate with disease severity
The Health Facility evaluated an observational study involving 212 patients in Southeast Asia with COVID-19, determining the correlation between vitamin D levels and disease severity. Those with the mildest disease had the highest vitamin D levels, and vice versa.
Out of 212 people, 49 have mild illness; 59 people with common diseases; 56 people are seriously ill and 48 are critical. In the initial study group of 212 patients (see Table 1 below), 55 had normal vitamin D levels, defined as greater than 30 ng/ml; 80 had a deficiency between 21 and 29 ng/ml and 77 had a deficiency below 20 ng/ml.
Now, it’s worth noting that the “optimal” vitamin D levels in that study were set at 30 nanograms per milliliter (30 ng/mL), which may actually be suboptimal. According to research conducted by Grass juniorHealth, 40 ng/mL is the bottom end of the optimal range, with 60 ng/mL to 80 ng/mL being ideal for health and disease prevention. Even so, the benefits of having vitamin D levels above 30 ng/mL are clear.
Vitamin D levels correlate with mortality risk
A second study looked at data from 780 hospital patients in Indonesia. Similar vitamin D thresholds were used in this study: less than 20 ng/mL; from 20 ng/mL to 30 ng/mL; and above 30 ng/mL.
After adjusting for confounding factors, those with vitamin D levels between 20 ng/mL and 30 ng/mL were seven times more likely to die than those with levels above 30 ng/mL. Having levels below 20 ng/mL was associated with a 12-fold higher risk of death. As noted by Hollis, “That’s really powerful data.”
It’s the vitamin D level in your blood that matters, not the dose
Currently, many studies on vitamin D conclude that vitamin D supplementation has little or no effect on any particular health problem or condition. But there’s a very simple reason for this: Almost every study used the same dose or dosage for everyone and didn’t measure the blood levels of the participants.
This is an important mistake, as blood levels actually need to cross a specific threshold, and the dosage needed to reach that level can vary widely. Another problem is that most studies use doses that are too low. If the dose is too low, you won’t be able to bring your blood into a protective threshold, and so it will appear as if vitamin D is useless.
A third factor that can affect the results of vitamin D studies is the interaction between vitamin D and other nutrients. A lack of competition may affect a particular subgroup or subpopulation, thereby confounding the results.
The fourth factor is how you define a deficiency – use a “word” relative to the serum level. For the Scientists’ Baseline Health 48 Research Panel, the consensus was that the serum level should be at least 40 ng/ml (100 nmol/L). Wagner explains:
“If you do a search on PubMed, you’ll see thousands of articles. You’ll find really rich background science information accumulated over the past two decades, strongly supporting the role of vitamin D in immunity.
But then, when randomized controlled trials were done, there were some who said vitamin D was effective and others who said no. It’s a controversial issue and I’m sure Bruce and Carole [Baggerly] would agree with me that doing nutrient studies is not the same as doing a pharmaceutical study where… they start with zero as the baseline.
[When it comes to] vitamin D [levels], everyone is different. And so using a biomarker, which we use in our studies, total cyclic 25(OH)D is a much better indicator. “
Hollis adds:
“In nutrient studies with vitamin D, it’s always the dose – how much you’re going to give – regardless of what the blood level will be.
Of course, in our studies we always measure blood levels. Those studies Carol [Wagner] and I did during my pregnancy (in 2003), they are monitored by the FDA. We had to have an investigational drug number (IDN) to do these studies and have never had to do that…
Finally, we proved [dosage] we [gave] – 4,000 units – completely harmless in dosage. But it’s still a fight… We’ve yet to see a single vitamin D-related side effect in any of the studies Carol did. [Wagner] and I did, not once…”
The law needs updating
Unfortunately, with labeling laws their way, it’s very difficult to deal with this. As noted by Baggerly:
“Basic health… [asked] FDA… for the possibility of printing on [label of] any vitamin D supplement’[Vitamin D] can help have a healthy pregnancy and [improve] birth outcomes. ‘ What we were told in that meeting by the FDA officer was, ‘By what dosage?’
We’ve explained many times that it’s not the dosage, it’s the serum concentration, and the person in charge of the FDA said, ‘By law we can only accept recommendations based on dosage, and if you don’t can provide us with dosage, we cannot accept any recommendations. ‘ So at least the law is out of date. “
Skin color affects your risk of vitamin D deficiency
Your skin color correlates with your vitamin D levels, and we also see racial differences in COVID-19. As noted by Hollis, in Detroit, Michigan, where African-Americans make up 14% of the population, they account for 40% of COVID-19 deaths.first
“It’s even worse in Sweden, where the Somali population is less than 1%, and they [account for] 40% of the deaths,” Hollis said. “In the UK, of the 24 health care doctors who have died, 23 are people of color. It’s so bad that they’re pulling those people off the front lines … doctors and nurses.”
Vitamin D deficiency may play a role in this racial difference, although prevalence of undernutrition, obesity, and diabetes also contribute to immune dysfunction. It’s important for people with darker skin to realize that the more melanin you have, the more sun exposure you need to make enough vitamin D.
According to Hollis, it is physiologically for a dark-skinned person in the United States, unless they are in South Florida or Hawaii, to get optimal vitamin D from normal sun exposure.
Daily supplementation can strengthen lung tissue
If for some reason you can’t get regular sun exposure, a vitamin D supplement is recommended. Ideally, you should take it daily, rather than taking a large dose of bolus once a week. or once a month. As Hollis notes, studies have consistently shown that just taking a daily supplement is effective.
“When they looked at bolus supplementation, the effect on respiratory infections was gone,” he says. “Dosing bolus every other week or once a month, every three months, is not effective in controlling respiratory infections. So we prefer daily [supplementation]. “
Baggerly adds:
“The vitamin D component is made in the skin by sun exposure at a stage that we use as a supplement, D3, and is then converted to 25(OH)D, which is What we measure, for the most part.
D3 and even 25(OH)D in the past have been considered inactive… In recent studies, and we’re actually talking relatively recently, D3 itself appears to be active in helping to keep the epithelium healthy. [to prevent endothelial leakage]. “
Vitamin D3’s ability to strengthen the endothelial structure of the lungs may be one way that vitamin D helps protect against COVID-19. “COVID-19 attacks the lungs… and the vitamin D in this model works to stabilize that,” says Hollis.
Vitamin D strengthens and regulates immune function
Vitamin D also has a clear effect on your innate immune system, which is your first line of defense against bacteria and viruses, as well as your adaptive immune system. T helper cells and natural killer cells.
All of this needs to be balanced, Wagner explains. If an imbalance occurs, you could end up with a cytokine storm. According to Wagner, vitamin D is very effective for regulating and balancing adaptive immunity. An example of the luxury of this system is pregnancy. Wagner explains:
“You go from a very active immune system, where you have, when the egg is fertilized, penetrate the uterine wall. You have to allow that, [and] it’s a very inflammatory state. Then to allow the growth of the fetus, you must have the tranquility of that [proinflammatory state].
You see changes in the T-cell population, the phenotype, as well as in the population of single-cell macrophages, their activity. And then, at the time of delivery, you switch back to a pro-inflammatory state [when you] labor and expel the fetus and placenta. So it’s an extremely elegant process.
We know that when it’s deranged, we get conditions like preeclampsia. You have inflammation of the blood vessels throughout your body and it can lead to death for both mother and fetus, and you can have a cytokine storm during that time. So COVID-19 is not like alien aliens; it uses the very immune system we have in our body and it makes sense.
Although this particular virus is new, it incorporates ancient systems within our bodies and includes a very ancient pro-hormone, vitamin D.
So for me, as a doctor and as a scientist, it makes sense for people to have a balance in their bodies and in this case a vitamin D balance, that they will function. act better than if they were in short supply. [because then] they can’t mobilize these [immune] cell. Those cells will be dysfunctional. “
Research has also demonstrated that pregnant women with optimal vitamin D levels significantly reduce their child’s risk of developing Type 1 diabetes, an autoimmune disorder. As noted by Baggerly:
“We’re working with the Diabetes Research Center to see if, even after the child is born, as long as they don’t have full-blown type 1 diabetes, what can we do to help prevent it? block it? And it turns out that the combination of vitamin D and omega-3 is really important.”
