Telepolis: Does vitamin D protect against Covid-19?

Telepolis: Does vitamin D protect against Covid-19?

Publication date: April 17, 2020

Telepolis article | My reply to comments on the article

On April 3rd, the SPIEGEL published a Fact Check:

Do vitamins protect against the coronavirus?

and summarizes the result briefly:

"Currently, people are praising vitamin C and D as a wonder weapon against Covid-19. Why you shouldn't be tempted to buy supplements right away, though."

The author and expert Nina Weber is once again completely in line with the DGE and the medical profession, who are unanimous in saying that anyone who consumes a balanced diet need not fear any deficiencies in vitamins or minerals.

The same applies, for example, to selenium. Because the European soils have been washed out for millions of years and are therefore low in selenium, we lack selenium in our bread. The Finns enrich their grain fertiliser with selenium. Germany does not. And Stiftung Warentest, the German consumer watchdog, also warns explicitly against selenium preparations: "Food supplement with selenium: Doesn't help much - harms in doubt". Nothing helps against what? Ah, heart attack. Who said that? Nobody. Classic tactic: disprove what the supposed "opponent" (= the dumb consumer) didn't even ask. And the warning? Yes, you can put a Chow-Chow in the microwave to dry. This will not end well. Yes, you can poison yourself with selenium by taking 7 times the daily dose for 6 months. That's not gonna end well either. It's not surprising, but who needs such arguments?

As far as vitamins and trace elements are concerned, one should therefore at least critically question the statements of the DGE, the medical associations and other professional associations, the Federal Nutrition Institutes such as the DIFe or the Federal Institute for Risk Assessment (BfR) and also compare them with international recommendations.

Example iodine: introduced in Switzerland as early as 1925 to combat cretinism and goiter. With 20 mcg iodide per 1g salt. In the FRG only "allowed" since 1985. In Switzerland, 2/3 of processed foods (sausage, pizza etc.) are produced with iodized salt, but in the FRG only 1/3. Switzerland has now increased the value in salt to 25 mcg/g. And we have iodine deficiency, it's great how the united federal science takes care of us.

But now to vitamins and the corona virus. SPIEGEL:

Attention! Before buying the largest possible pack of vitamin D online immediately: To take it is only advised (Source: DGE), if there is indeed an undersupply, i.e. if a too low value is proven and a better value cannot be achieved by staying in the sun as well as by nutrition.

Those who have enough vitamin D anyway probably do not benefit from additional pills. You can overdose on vitamin D and harm yourself. This can to Example lead to kidney stones."

Oh, that's almost all wrong. Starting with the package size, which has nothing to do with the contents of the single daily dose, right? 100 of ASA has the exact same 500 mg tablets in it as a 20 pack. Well, the author doesn't want to talk about dosages, that's dangerous territory, too.

An undersupply? Yes, there is, especially among the elderly. This is what the BfR tells us in a paper from 2011 (there is no newer one) in two nice graphics:

Yes, the "healthy" seniors range from 66-96 years (arithmetic mean would be 81), but the multimorbid seniors (geriatric is a nice euphemism for multimorbid or pre-existing conditions) are about 83 years old (or 78-88 years). Nevertheless, the correlation between ill and undersupplied and healthy and well supplied is obvious.

However, the original German limit value of 20 ng/ml (=50 mmol/L, conversion factor is ~1:2.496) is also reproduced here, which should be considered healthy, no, even "optimal". This has long been different internationally, usually <20 ng/ml is considered deficient, 20-30 ng/ml is insufficient and only >30 ng/ml is sufficient.

One could add: in the cradle of mankind, in East Africa, the traditional Masai and Hadza tribes living there have a level of 46 ng/ml:

Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115 nmol/l." (

Wild chimpanzees, our most genetically similar cousins have 48 ng/ml. In European zoos, however, only 24 ng/ml, similar to us: Average German population: 18 ng/ml - annual average. Since vitamin D is hardly ever supplied by food, but is formed by UVB, i.e. sunlight, but is no longer produced between October and March due to the position of the sun, and the D storage only lasts for 2-3 months, values of <10 ng/ml in January and February are by no means rare, especially not in senior citizens: 40% of the over 65-year-olds have - on an annual average - only less than 10 ng/ml, another 40% less than 20 ng/ml. All according to the BfR. What might be going on there in January when the flu is raging?

But correlation does not equal causality. The most famous example of a "fake" causality with high correlation is probably still the decrease in the number of storks with the decrease in the birth rate. Both are indirectly related to industrialization, but still the old wives' tale that the stork brings babies does not become more true.

What's the point of causality? The fact that in the case of real influenza caused by influenza viruses, it is mainly the elderly who die of pneumonia is no proof, even if this correlates highly with the vitamin D level, which decreases with age (elderly people only produce 25% as much vitamin D as young people, and there is also another social behaviour: naked sunbathing is the exception rather than the rule).

For vitamin D deficiency is only a Disease really undisputed: rickets (softening of bones). And this is reliably prevented with a daily dose of about 1000 international units (I.E. or IU), pretty much the content of a spoonful of cod liver oil that was once given to children. 1.000 I.U. or 25 mcg D3 will lead to an additional level of about 10 ng/ml D(25), depending on the previous level - if you already have "45" you will only gain "5", the body has a built-in brake. Cholecalciferol is sold as D3, a precursor of the active vitamin D (calcitriol) which is later produced by the body from it, which is actually a hormone or secosteroid. However, a doctor will measure the intermediate stage calcidiol or 25(OH)-vitamin D, or D(25) for short, in which it is stored in the body.

Analogous to iodine: cretinism is recognized in cases of severe deficiency, in moderation also the goiter (goiter). There is little or nothing in the literature about whether a less severe deficiency leads to under- or overactive thyroid glands. And in everyday life we usually do not notice any iodine deficiency. But at the same time we see an absurdly high number of thyroid operations, because 80,000 operations/a means that every 10th German is operated on the thyroid gland in the course of his life. Which then each one accepts as an individual fate. Correlation or causality? An eternally undersupplied thyroid gland that reacts by failing, ceasing to function, or becoming hyperactive to compensate for the deficiency? Would it be necessary to test double-blind over 30 years. Iodine costs nothing, thyroid hormones, which are taken for the rest of your life after a resection, cost considerably more. You can't make money with iodine, but you can make money with surgery. There is no incentive for expensive studies, because such studies are almost exclusively financed by the pharmaceutical industry - which cannot earn anything with iodine, but with T3/T4 replacement can.

Back to vitamin D. What else does it do besides prevent rickets? It is involved in the synthesis of more than 2000 proteins and enzymes in the body, so one would rather ask: what does it not do? And some of these enzymes control our immune system, D is considered an immune modulator. Because the war that our body is waging against inflammations of any kind, be they bacterial or viral, has to be moderated, there have to be enough "warriors" around and they have to be able to be sent into battle quickly, but if there are too many of them, they inevitably attack their own people, the healthy cells, and produce so many cytokines (cell toxins) in their defensive fight that a dreaded cytokine storm (= even more warriors) is triggered, which all too often ends in sepsis and multiorgan failure.

On February 6, Prof. Chrstian Wendtner, chief physician in Schwabing and infectiologist on Bavarian radio said Corona is no more dangerous than influenza. ( But only seven weeks later in the ZEIT-interview: "We also intubate and ventilate young people. [..] In many patients [...] huge areas of the lungs are infected. "This is a very powerful thing that is happening here." In many cases there is an excessive reaction of the immune system, a cytokine storm. "In simple terms, inflammatory cells shoot into the lungs. This severely restricts the function of the alveoli and the gas exchange cannot function. In the majority of patients who come into intensive care, we see a reaction like this at some point."

"Especially in prematurely ill and old people whose immune system is weakened, sars-CoV-2 can literally destroy the lungs. On the one hand, the enslaved epithelial cells perish over time, on the other hand, the body's own immune cells apparently attack the inflamed lung. says Corona researcher Hilgenfeld at MIRROR

And what does vitamin D have to do with it? As I said, D is an immunomodulator, downregulating the immune response is as much a part of its functions as providing the army of immune warriors. A solid balance between the two ensures that the body deals with inflammation in a sensible, balanced way.

The assumption is that a solid vitamin D level (rather in the Masai/Hadza area, i.e. more likely 45-50 ng/ml, than the German 20 ng/ml) could very much reduce the incidence of cytokine storm and sepsis. Less sepsis, fewer deaths, shorter ventilation, shorter stay in intensive care, less congestion in hospitals, less lethality. I don't have to explain here what this would mean for society as a whole, that's how smart Telepolis readers are. But why don't we notice anything of the rather deficient vitamin status in everyday life? As with iodine: one would not think that, for example, the 1-3 colds a year with three to seven days of cold could be reduced to half a day with a somewhat irritated nose if the D-level was higher and the body could immediately fight the rhinoviruses properly. This cannot be proven either, especially not by personal experience, which is always considered "anecdotal". Look at it this way: with only half the air pressure on the tires you can comfortably drive to the supermarket and back at any time, you won't even notice that if you don't have a very sensitive Sebastian-Vettel-Popometer. Only if you had to make an emergency stop or go through a very sharp curve unexpectedly too fast, this could become very critical, make the decisive difference. That means: in "healthy" everyday life there is no indication of too little D, only when it is needed in critical, i.e. sick situations, does it become exciting.

So now to the clues, to the studies. First there is an Iranian study - almost unknown (who believes Iran?) and in my opinion not mentioned anywhere in the Corona discussion until April 3. Why should it be, has nothing to do with Corona. The author had found it by chance on the net while searching for vitamin D and sepsis and had pointed it out to the MIRROR. A few days later she was taken up in the above mentioned vitamin article and was torn to pieces:

"The Relationship of Serum Vitamin D Level With the Outcome in Surgical Intensive Care Unit Patients" (

vitamin D level

Vit D < 20 ng/ml

Vit D 20-30 ng/ml

Vit D > 30 ng/ml

Average age

66,2 +/- 14,6

65,3 +/- 14,3

53,7 +/- 17,3





Days ICU:




Note: 1st and 2nd group are almost the same age (~65/66), third group only 54, but with a very wide range, 36-70 years.

Despite this limitation of comparability: we see from little too much vitamin D a halving of the duration of stay in the ICU (24/12/6), in sepsis the effect is even greater (~36/~18/~3), which already smells strongly of causality, especially since the effect of vitamin D on the immune system is sufficiently known. And it fatally coincides with what we know about the dying, especially of old, previously ill seniors and their correspondingly low vitamin D levels (see BfR statistics above).

But what does the SPIEGEL think (which, interestingly enough, has taken up this completely unknown study)?

At first glance, the data seem to provide a clear picture: vitamin D deficiency was associated with a higher risk of sepsis and death. However, the researchers themselves make it clear that vitamin D deficiency is not the trigger but a concomitant symptom of the previous severe chronic diseases of the patients, and that it helps to determine the overall condition of the patients.

This is a more than free interpretation and is not included in the study. What it says is that other possible "co-factors" of the sepsis symptoms have been found: calcium, phosphorus levels, etc. And therefore cannot say that vitamin D is a biomarker for the probability of sepsis or its course.

Now, however, the calcium/phosphorus metabolism is manifoldly linked to the vitamin D metabolism, as Wikipedia teaches us. Since the study does not contain any further information on the calcium and phosphorus values, it is unfortunately not possible to check what is hen and what is egg. If all factors point in the same direction (reciprocal or not, depending on whether they do or not), this would not be surprising, because we know one thing for sure: the calcium metabolism is dependent on vitamin D, not the other way around. And yes, it is known that vitamin D is "consumed" by serious diseases (cancer etc.). But the authors had prospectively measured on admission to the ICU, not afterwards!

And there are more studies that are looking at pneumonia and vitamin D. A major met analysis in 2017 over a total of 11,000 patients comes to the conclusion

Vitamin D supplementation was safe and provided overall protection against acute respiratory infections.

Results 25 eligible randomised controlled trials (total 11 321 participants, aged 0 to 95 years) were identified. Vitamin D supplementation reduced the risk of acute respiratory tract infection among all participants (adjusted odds ratio 0.88, 95% confidence interval 0.81 to 0.96; P for heterogeneity <0.001).
Conclusions Vitamin D supplementation was safe and it protected against acute respiratory tract infection overall. Patients who were very vitamin D deficient and those not receiving bolus doses experienced the most benefit.

and this study here: DOI: 10.21203/ comes to the following results

The mean vitamin D level in each country was [...] strongly associated with mortality / 1 M.

Discussion: Vitamin D levels are very low in the ageing population, especially in Spain, Italy and Switzerland. [...]

Results: The mean level of vitamin D (average 56mmol/L, STDEV 10.61) in each country was strongly associated [...] with the mortality/1M (mean 5.96, STDEV 15.13, p < 0.00001).
Discussion: Vitamin D levels are severely low in the aging population especially in Spain, Italy and Switzerland. [...]
Conclusions: We believe, that we can advise Vitamin D supplementation to protect against SARS-CoV2 infection.

And there's still more: One English Study comes to very similar results (translated and shortened):

81 Patients, mean age 62 years. Patients with D-values of <30 ng/ml were more likely to have severe sepsis (61% vs. 24%; p = 0.006) and dysfunction of two or more organ systems (50% vs. 18%) compared to patients with D-values of >30 ng /ml. All four patients who died during the index hospital stay had 25 D levels of <30 ng/ml.

The small number of patients does not allow reasonable statistical significance, clearly. But a true prospective
study which took place at a training hospital in Boston points in the same direction. There, 3 x 10 ICU patients were examined for D-level immediately after admission and then treated with placebo, 200,000 IU and 400,000 IU respectively. Statistical significance cannot be expected in only 30 subjects, and some initial values differed: the placebo group (1) had the highest D-level at the beginning (after 5 days then the lowest), group 3 with 400,000 IU initial dose had the highest BMI. After all, the age average was relatively balanced. In the result one can emphasize above all: Days in the ICU: 12 / 4 / 3. Resumption in the ICU within 30 days: 20% / 0% / 0%. 30 days mortality: 30% / 30% / 20%. None of this is significant, but the trend is unmistakable.

In the last few days, there have also been two reports on portals that are rather appreciated by medical professionals: mitigation - colecalciferol and covid-19/

American scientists, in collaboration with researchers from the Medical University of Debrecen, Hungary, evaluated data on vitamin D and infections. Now they suspect that vitamin D supplementation can be seen as a useful risk reduction measure in the current corona pandemic. This possibility is based on the release of cathelicidins and defensins. Cathelicidins are antimicrobial peptides and part of the innate immune response. They are mainly produced in immune cells of vertebrates and serve for apoptosis of endogenous cells. Defensins are also peptides. They occur as antimicrobial peptides in all animal organisms and serve to defend against microbial pathogens, especially bacteria, fungi and toxins. These peptides could reduce virus replication rates. At the same time, the number of inflammation-promoting cytokines could be reduced. The scientists assume that a low concentration of cytokines in the body leads to fewer secondary diseases such as pneumonia.

And here three publications are cited, of which the second and most interesting one has unfortunately already been withdrawn by the authors (allegedly because of idosyncratic vitamin D levels in various countries). And the third one I already quoted above.

There is therefore sufficient reason to investigate a correlation between vitamin D levels and the course of covid-19 disease. The D-level is very low, especially in elderly people, and even lower in those with previous diseases (geriatric/mulitmorbid), says the BfR, but this is exactly the population group with an enormously high lethality of Covid-19. This does not sound like a coincidence.

And: Mother Nature is not known for maintaining energy-hungry processes in the body "just for fun". Example: muscle loss when not in use - anyone who has ever had to complain about a torn Achilles tendon knows that the calf degenerates into a thin sausage within a few weeks "lockdown". Saving energy is the iron commandment of the body, instead of wasting energy, it is better stored in fat pads, if possible - for bad times. And since muscles also consume energy at rest, they are quickly broken down when not in use.

So why should primitive peoples and chimpanzees synthesize energy-intensive 45-50 ng/ml vitamin D, if it would not be evolutionary beneficial? And the advantage would be a good immune defence - which is certainly needed earlier in the bush with thousands of possible injuries and a high number of infectious germs than in our disinfected, clean-cut high-security world with the lowest risk of injury? Because, as individual cases show, even a small skin tear, caused by a splinter of wood, can (in our case) lead to sepsis. In the wild and without intensive care medicine for emergencies, this would not be affordable.

Why do we in Europe only have less than 20 ng/ml? Because even our white skin is not able to provide more here, as little as we are outside. Until 5,000 years ago we were also dark-skinned, which apparently was not as successful in evolutionary terms as light-skinned skin, and vitamin D is the most plausible explanation for this. By the way, Israeli lifeguards often have a D-level of 60 ng/ml, so you would only have to be outdoors a lot and live on the Mediterranean Sea...

However, the beach guards also have many more kidney stones at a young age. So here's a short info, which has nothing to do with Corona but is absolutely important: To reach levels of this height through supplementation, the average adult would not have to consume the 800 I.U. (20 mcg) D3 usually prescribed by the DGE/doctors, but 4,000-5,000 I.U. per day. But that's without additional vitamin K2 is not recommended.

K2 is only present in food in very small quantities; in fermented food, e.g. in sauerkraut or kvass, would be enough, but who still eats sauerkraut or drinks fermented bread soup today? In principle, K2 can also be synthesized by the body from K1, but for amounts needed with a D-level of 45-50 ng/ml, we would have to eat much more greens than we do (the chimpanzees do, of course). And the fact that our today's over-fertilized turbo vegetables contain far less "vital substances" has been criticized many times, most recently by star cook Nelson Müller testified on TV regarding vitamin C in South Tyrolean apples, there was the content: zero-command zero.

However, an imbalance between D and K2 inevitably leads to hypercalcemia. We rather don't get it with our small D levels, but the Israeli beach guards do, if they eat falafel and hot dogs.

K2 ensures the correct distribution of the calcium. Without K2, a high D-level additionally dissolves calcium from the bones and aggravates osteoporosis, despite additional calcium administration. Unfortunately, this has been proven by many studies, which also had to document other consequences of hypercalcemia: in addition to kidney stones, increased calcium plaque and subsequently heart attacks and strokes, and in the case of very severe hypercalcemia, kidney damage up to failure. Therefore: Vitamin D never without correspronating vitamin K2 (not 'K' or K1, not mk4 but mk7, not cis but preferably alltrans). Doses of 40 mcg K2 mk7 alltrans per 1000 I.U. are reported and partly mixed with D-preparations (Caution all heart & thrombosis patients taking "blood thinners" of the vitamin K antagonists class such as Marcumar or Coumadin, read here:

It has to be said quite clearly: all negative studies on vitamin D (most recently one from 2013-2017) were without accompanying K2 and this although the mechanism of action of K2 is known since 1985. Vitamin D in high doses without K2 would have to be described as malpractice and negligent bodily injury. Whereby "high" means anything above 800 I.U./d, but on the other hand, such doses never reach the Massai/Hadza level.

Last-not-least: Everything possible is measured in patients on intensive care units, except the D-level. Costs a whole 17 euros in the laboratory. No measurement, no values, therefore no possible connection that could be noticed by the staff.

For the general practitioner for patients covered by health insurance, it costs 30 euros, which are usually not covered by the health insurance. This is why measurements are rarely taken there, which means that the correlation between the D-value and health status is not even noticeable there - the data is far too thin for a correlation that can be "felt" for the time being, so we should not expect anything from the practitioners. Nor should we expect anything from our leading experts, as an interview on NDR radio on April 3, 20 shows:

Anja Martini: Can we do more, can we for example do something for our immune system and build it up, maybe vitamin C, vitamin D [...]

Drosten: [...] So taking any things, any vitamins, there may be scientific evidence for that here and there, but that's not my field of research, I don't know anything about that, and I've never heard that there's a resounding effect somewhere, so that one would now say, in the context of such an ongoing epidemic of infections one has to recommend it specifically.

The author has offered a severely affected district 5,000 euros for ex-post vitamin D tests to be carried out on 120 Covid-19 patients with different disease courses - unfortunately without success. But sometime in the future, such tests and the resulting statistics will be available. The result is quite predictable. And At some point, the SPIEGEL will also have to correct its vitamin article, at the latest when the government prescribes vitamin D for all nursing homes and medical staff.

Covid-19 will never be a simple influenza and vitamin D will never be able to "cure" Covid-19. But it could help the body to weather the infection much better than the too low D-levels have done so far. And thus make the pandemic more manageable. Anyone can imagine what this means.

Last-not-least: There are absolutely no known harmful side effects of a D-level of 50 ng/ml (with appropriate K2 supply), toxicity starts according to all references only at approx. 140-150 ng/ml, a supplementation of 5,000 I.E/d D3 at 70 kg body weight and corresponding supply of 200 mcg K2 is considered completely safe.

Heidelberg, 16.4.2019, Lorenz Borsche