In this article I’ll be making the case that Vitamin D is absolutely essential, and for many people the most essential, for building an immune system that’s well-equipped to fight off cold and flu, pneumonia and the stupid dumb Corona Virus.
I’ll go through a smidge of studies here to make my case, with special focus on human studies dealing specifically with respiratory tract infections, pneumonia, and COVID-19..
Based on the studies shown below and research presented elsewhere, it seems one would want their Vitamin D blood levels in the upper end of the reference range. The lower-end of the reference range seems to be not nearly as good. The vitamin D council’s recommendation to try to achieve this blood level is to supplement with 1000 IU per 25 lbs of body weight per day. It also looks like they’re probably being reasonably conservative as well, and accounting for modest sun exposure. In my opinion the best thing to do is to supplement daily and test blood levels a couple of times per year to ensure you’re where you want to be; again, within the high end of the reference range, somewhere around 50 ng/ml seems optimal for health, and over 150 ng/ml is where negative effects really come into play; though there is evidence they are somewhat mitigated by good vitamin K2 status. Vitamin D3 is often sold with K2 for this reason, and I always recommend getting them together.
Before we get to the studies, I think a little context is important. The context is this: Humans have spent most of our evolutionary history outside, under the sun. I’m talking about from the dawn of multicellular life, to the age of medieval farming and beyond. The last 100 years, but in particular the last 50, represent a dramatic change in this behavior; now most of us spend most of our time indoors.
This has not only messed up our biological clocks but our vitamin D status; which is crucial for our immune system. I’d go as far as to say, the most critical element – not to take away the importance of various other factors such as exercise, diet, stress, and so on. But if I had to pick one thing… Vitamin D status not only improves the ability to fight off cold and flu, but has been shown over and over again to play a key role in autoimmune conditions and cancer prevention.
Virtually every historic civilization worshipped a sun-god or the sun itself. Modern medicine has told us to fear it.
I want to start with some studies on COVID-19; maybe that’s what you’re here for.
In May of this year a group published a paper in the journal Aging Clinical and Experimental Research, looking at mean vitamin D levels by population in each European country, and how badly those countries were hit with COVID-19. They noted that the worst average blood levels of Vitamin D were found in Italy, Spain, and Switzerland. Rather than get into the minutia of what they discussed, a picture is worth a thousand words, and we can simply look at their charts:
So, the first chart there is Mortality (y-axis) vs Vitamin D status (x-axis), and the second one is simply the number of Cases (y-axis) vs Vitamin D status (x-axis), both of which show a clear (and statistically significant, p value = 0.05 for both) trend towards fewer cases and fewer deaths occurring with higher average blood levels of Vitamin D. There’s enough variance there to be sure that Vitamin D is not the only factor, but certainly it is a very significant one.
Second, a research team led by Northwestern University conducted statistical analysis of data COVID-19 patients around the world; from hospitals and clinics in China, France, Germany, Italy, Iran, South Korea, Spain, Switzerland, the UK and the US. They looked at a number of metrics and blood markers and one of the things that stood out was that patients with low levels of Vitamin D had a very strong correlation to high C-Reactive Protein (CRP). CRP is a blood marker for indicating overall inflammation levels. They then found a very strong correlation between high CRP and severity of COVID-19 symptoms (and death).
As we read their synopsis below, keep in mind that OR means Odds Ratio; anything higher than 1 is an increased odd (So generally speaking OR of 2 for instance, means chances are doubled, OR of 4 means chances are quadrupled, etc), and anything less than 1 is a decreased odd (An OR of 0.5 for instance, indicates 50% reduced chance of something happening).
“Our analysis determined a possible link between high CRP and Vit D deficiency and calculated an OR of 1.8 among the elderly in low-income families and an OR of 1.9 among the elderly in high-income families. COVID-19 patient-level data shows a notable OR of 3.4 for high CRP in severe COVID-19 patients.”
In other words if you have low vitamin D, you’re almost twice as likely to be a high-inflammation COVID-19 patient, and if you’re a high-inflammation COVID-19 patient you’re 3 or 4 times more likely to have very severe symptoms, including death.
An independent researcher, Christopher Fields, gathered studies and meta-analysis on Vitamin D blood insufficiency levels by country, and plotted it against COVID-19 deaths per million people. Posing the question: “How is it that Somali-Swedes make up 40% of all COVID-19 deaths in Stockholm, and African-Americans make up 40% of COVID-19 deaths in the US? African-Americans are 13% of the US population, Somali-Swedes are less than 1% of the Swedish population.” The data he gathered looks like this:
He said this about his research: “For every 1% increase in Vitamin D deficiency in a country’s population, there is a 5.5-fold increase in death rate.”
The implication in his question, by the way, is that people with darker complexions (more of the natural sun-block known as melanin, in their skin) tend to have lower vitamin D levels, in particular when they live in regions further from the equator.
There was also a study from Davao Doctors College, where they looked at 212 patients with laboratory confirmed infections of SARS-CoV-2. “Serum [Vitamin D] level was lowest in critical cases, but highest in mild cases. Serum [Vitamin D] levels were statistically significant among clinical outcomes.”
Unfortunately there is no pretty chart here, but if you take a second to look at the table from this study, the results kind of pop off the page at you:
In the bottom three rows we see the Vitamin D status by patient, grouped into Normal, Insufficient and Deficient, and if we look at people who were Severely or Critically Ill with COVID-19, almost none of them had normal Vitamin D levels (2 and 2 respectively) where as most had insufficient (23 and 21) or completely deficient (31 and 25). Talk about a stark contrast!
For each standard deviation increase in serum vitamin D people were 7.94 times more likely to have mild rather than severe COVID-19, and were 19.61 times more likely to have a mild rather than critical outcome.
And finally, a paper that’s yet to be published from Dr. Prabowo Raharusuna looked at 780 cases of laboratory-confirmed infection of SARS-CoV-2, examining the variables of age, sex, co-morbidity, vitamin D status and disease outcome. Vitamin D is what stood out. Again, a picture paints a thousand words:
Like the other studies, this data looks so compelling that, if correct, one concludes that high Vitamin D status is the number one way to prevent severe and critical cases.
Some of these studies prompted the submission of a great paper to the British Medical Journal authored by a group of doctors, titled “Is ethnicity linked to incidence or outcomes of covid-19?” Here is their introduction:
“COVID-19 (Coronavirus) mortality disproportionately impacts BAME (Black, Asian and Minority Ethnic) UK individuals, African Americans, Swedish Somalis, and the institutionalised; particularly care-home residents. COVID-19 severity and mortality, appear related to vitamin D deficiency, helping explain higher COVID-19 mortality rates in BAME and the obese.
Obesity is a strong COVID-19 risk factor, as are co-morbidities, including diabetes, cardio-vascular disease; and sedentary lifestyle; all are dependent on mitochondrial functionality (Gnaiger). Fat cells accrete vitamin D. The obese consistently have proportionately lower vitamin D status (serum 25-hydroxyvitamin D [25(OH)D]).”
Those are all the studies thus far which have examined the relationship between COVID-19 and Vitamin D. However, complications and deaths from COVID-19 are caused by the symptoms in a sense, the not the virus. You die from not being able to breath due to a respiratory tract infection, not an excess of viral material, so to speak. So in the next few paragraphs I’ll look at studies related to vitamin D’s effect on respiratory tract infections, such as pneumonia, and see what protection it might offer in terms of tamping down the symptoms or avoiding them altogether.
Heliotherapy as a form of medicine dates back at least 1200 years. It was used to treat smallpox, lupus and tuberculosis, and improve wound healing time among other things. Seen here are Polio and arthritis patients in beds on the roof of a hospital.
First a new 2019 meta-analysis looking at Vitamin D and Community Acquired Pneumonia (in other words, viral-pneumonia) and published in the journal Medicine. The analysis included almost 21,000 subjects. That is a huge study! As you read the paragraph below, keep in mind they abbreviate this kind of pneumonia as CAP. Here’s what they said:
“In this meta-analysis, CAP patients with vitamin D deficiency experienced a significantly increased risk of CAP (odds ratio = 1.64), and an obvious decrease of -5.63 ng/mL in serum vitamin D was demonstrated in CAP patients. Sensitivity analysis showed that exclusion of any single study did not materially alter the overall combined effect.The evidence from this meta-analysis indicates an association between vitamin D deficiency and an increased risk of CAP patients.”
A pretty meaty odds ratio there, just between being Vitamin D deficient and ‘normal’ levels of vitamin D. An odds ratio of 1.64, means the vitamin D deficient people were 64% more likely to get CAP compared to people with normal levels. Keep in mind that normal does NOT mean optimal. If normal levels of vitamin D are significantly below optimal levels, which I believe is the case, we likely would have seen an odds ratio of closer to 2, which would mean Vitamin D deficient people are perhaps twice as likely to acquire pneumonia compared to those people with optimal levels.
Another study on pneumonia, this out of Kabul and published in 2010 looked at the effect of Vitamin D supplementation. The study was called “Effects of vitamin D supplementation to children diagnosed with pneumonia in Kabul: a randomised controlled trial” and they gave kids with pneumonia 100,000 IU of vitamin D, or placebo, along with antibiotics to treat pneumonia. The study involved 450 kids.
The results?
“There was no significant difference in the mean number of days to recovery between the vitamin D3 and placebo arms. The risk of a repeat episode of pneumonia within 90 days of supplementation was lower in the intervention than the placebo group . Children in the vitamin D3 group survived longer without experiencing a repeat episode (72 days vs. 59 days; HR 0.71).”
In other words, taking Vitamin D after they were sick made no difference, however even a large one-time dose was found to be preventative to future illness and recurring infection. Research since this study was published indicates that single large mega-doses of Vitamin D are not nearly as good as taking the same amount spread out in daily doses.
In 2012 a systematic review and meta-analysis called “Vitamin D for prevention of respiratory tract infections: A systematic review and meta-analysis” looked at 5 high quality placebo controlled trials on vitamin D supplementation and found that:
Events of respiratory tract infections were significantly lower in vitamin D group as compared to control group [Odds ratio = 0.582] according to random model. Results were similar in fixed model. On separate analysis of clinical trials dealing with groups of children and adults, beneficial effect of vitamin D was observed in both, according to fixed model [Odds ratio = 0.579 and Odd ratio = 0.653 respectively].
In other words, no matter how they sliced the data, results showed vitamin D reduced respiratory tract infections (ie, cold & flu) and in a big way. The average dose in this meta-analysis was 1200 IU per day, which according to the Vitamin D council is totally appropriate if you weigh 30 lbs. In other words, most of these studies were severely under-dosed (meaning blood levels of vitamin D were likely not getting to that sweet spot up near the top of the reference range) and still found a big effect.
A huge epidemiological study of 18,000 people from 2009 and published in the Archives of Internal Medicine found:
“Even after adjusting for demographic and clinical characteristics, lower Vitamin D levels were independently associated with recent Upper Respiratory Tract Infection. The association between Vitamin D level and Upper Respiratory Tract Infection seemed to be stronger in individuals with asthma and chronic obstructive pulmonary disease (OR, 5.67 and 2.26, respectively).”
In other words lower vitamin D levels meant more instances of colds & flu. Low vitamin D levels plus long-term health conditions affecting the lungs, like asthma, meant way more instances of colds and flu (compared to high levels of vitamin D but a chronic condition affecting the lungs).
RAPID FIRE ROUND!
Let’s go through a few more studies very quickly, just to establish that there is a large body of evidence supporting Vitamin D’s efficacy, whether we’re talking about blood levels or supplementation. Let’s keep in mind also how this relates to the flu shot, which in it’s best years shows a relative risk of getting the seasonal flu of about 0.5 and in its worst years about 0.7.
A 2010 study called ‘Serum 25-hydroxyvitamin D and the incidence of acute viral respiratory tract infections in healthy adults’ found that Vitamin D blood “concentrations of 38 ng/ml or more were associated with a significant two-fold reduction in the risk of developing acute respiratory tract infections and with a marked reduction in the percentages of days ill.” This might indicate for instance, that if you are vitamin D deficient, raising blood levels about 38 ng/ml could be as effective as the flu shot.
A study titled ‘Vitamin D supplementation to patients with frequent respiratory tract infections: a post hoc analysis of a randomized and placebo-controlled trial’ found that Vitamin D supplementation increased the probability to stay free of Respiratory Tract Infections (RTIs) during the study year (RR 0.64). Further, the total number of RTIs was also reduced in the vitamin D-group (86 RTIs) versus placebo (120 RTIs). So, it cut the risk or RTI’s by more than a third, on a dose of 4000 IU / day; that dose is at least getting close to what we want.
A 2018 study called ‘Preventive Effects of Vitamin D on Seasonal Influenza A in Infants: A Multicenter, Randomized, Open, Controlled Clinical Trial’ found that of 121 cases in total, 78 and 43 cases of influenza A infection occurred in the low-dose (400 IU/day) and high-dose (1200 IU/day) vitamin D groups, respectively. Among the cases of influenza infection, the median durations for fever, cough, and wheezing were shorter in the high-dose vitamin D group than in the low-dose vitamin D group.
A 2010 study called ‘randomized trial of vitamin D supplementation to prevent seasonal influenza A in schoolchildren found that Influenza A occurred in 10.8% children in the vitamin D3 group compared with 18.6% children in the placebo group [relative risk (RR), 0.58, p < 0.05]. The reduction in influenza A was more prominent in children who had not been taking other vitamin D supplements previously. Again, we see almost a 50% reduction with what I would say is a small dose of 1200 IU / day (a dose appropriate for a 30 lbs child, whereas the average age of the children in this study was 11 years old. 3000 IU / day would have been better).
With the research behind us, just a couple of things to note about Vitamin D. Personally I feel brand name supplements aren’t too important here, as long as the brand is trustworthy enough that they’re actually putting what they say in the bottle! I find the easiest approach is to take liquid drops, and I personally take this product from NOW Foods but this one from Canprev, or this one are equally good – my preference for these ones stems from the fact that they use the MK-7 form of Vitamin K2, which seems to be the best form.
Also very critical, new evidence suggests that it is important to make sure you have sufficient magnesium status while taking D3, otherwise D3 will be of no benefit! Recent studies have shown magnesium deficiency at somewhere between 50% and 75% of all people in the United States. There’s no reason numbers wouldn’t be similar in Canada. Magnesium is a very safe supplement, very difficult to overdose on (unless you take the whole bottle at once, perhaps), and worth taking for a myriad of reasons. This product is a great form of magnesium, at a great price, in a reasonable bulk-sized bottle that should last 120 days if you take 2 capsules per day. Brand-name here is much less important than the form of magnesium. Glycinate or Bisglycinate seem to be best overall. Citrate is a good form if you suffer constipation, and magnesium L-threonate is the desirable form if you have issues with your central nervous system or brain.
Finally, summer is coming! In the summer I do drop my Vitamin D intake, usually to 2000 IU per day (from about 6000 IU normally), and try to get at least 30 minutes, hopefully 60 minutes of direct sunlight on my skin daily (no sunscreen). I think sunlight is likely a better way to get vitamin D than supplementation, but don’t allow yourself to burn. If skin damage is problematic for you, I’d consider ways to mitigate that; several fruits and vegetables such as melon, blueberries, carrots and tomatoes have sun-protective effects when consumed, as does the medicinal mushroom Chaga and green tea. UV rays of course do damage, but our bodies should be easily able to protect against it! We’ve had 2 billion years of evolution with much more UV exposure than we have now. So if sun damage is an issue, I’d look to diet and lifestyle to help, rather than blame our natural environment. It seems primarily our body’s ability to produce the endogenous antioxidant, superoxide dismutase, has a lot to do with how well we can fight damage from UV. Our bodies need sufficient copper and manganese to produce superoxide dismutase. The supplement GliSODin is a way to take superoxide dismutase directly, and it really does work for preventing UV damage.
Good luck out there!
