Tuesday, February 09, 2021
No scientific evidence
Experts: Vitamin D doesn’t help with Covid-19
In the corona pandemic, many people want to know how they can still protect themselves from Covid 19 disease. The intake of vitamin D supplements is then repeatedly mentioned. But experts do not give the green light for this.
Recommendations for taking vitamin D preparations are making the rounds on the Internet – currently also justified with information that this could prevent an infection with the corona virus or a severe course of Covid 19 disease. Appeals are circulating to provide the population with vitamin D supplements. Observations from clinics in several countries are cited as evidence of the need.
A clear cause-and-effect relationship between the vitamin D level and an increased risk of Sars CoV-2 infection or a severe course of Covid-19 has not been proven. Observational studies in European and US hospitals have shown that vitamin D deficiency is more often found in Covid 19 patients than in control groups. It has also been reported that people with low vitamin D levels tend to die more often from the condition than others.
Attempts were made at the Reina Sofia hospital in Madrid to get to the bottom of the matter: 50 Covid 19 patients were given vitamin D, only one of them ended up in the intensive care unit. In a control group of 26 patients who were not given any vitamin D preparations, however, half had to be treated in intensive care and two of them died.
Criticism of the investigation method
However, the Spanish study quickly came under fire. On closer inspection, it became clear that in the second group – the patients without vitamin administration – more previous illnesses, such as high blood pressure and diabetes, were registered and thus more risk factors for a severe course of Covid-19. “If you put the (relatively) healthy people in the vitamin D group and the (relatively) sick people in the control group, then it is clear beforehand what the outcome will be”, complains about Martin Smollich, pharmacologist and professor at the Institute for Nutritional Medicine at the University Hospital Schleswig -Holstein in Lübeck.
Smollich emphasizes that a causal connection between vitamin D deficiency and Covid-19 cannot be proven. Rather, a low vitamin D level measured at hospital admission could be a consequence (and not the cause) of the Covid 19 disease. In the context of an acute, severe infection, the vitamin D level drops drastically in the short term. In addition, a vitamin D deficiency “occurs more than average in diseases and living conditions which in turn increase the Covid 19 risk, i.e. in old age, with obesity or with type 2 diabetes”.
The Frankfurt virologist Sandra Ciesek explained in the NDR’s Corona podcast that the risk of a vitamin D deficiency generally increases in people who are rarely outdoors. This applies, for example, to the chronically ill or those in need of care who may no longer be able to eat well. Exactly this group is also considered to be particularly at risk of Covid-19.
So far everything is pure guesswork
The German Nutrition Society (DGE) has taken a close look at the current study situation and has come to the conclusion: A connection between a low vitamin D level and an increased corona risk can be suspected. However, the results of previous investigations were not sufficient to demonstrate a clear cause-effect relationship. Therefore, the intake of vitamin D supplements cannot be recommended across the board.
The Federal Institute for Risk Assessment (BfR) is also currently not aware of any studies that prove that taking vitamin D preparations protects against infection with the corona virus or illness. It is scientifically undisputed that vitamin D contributes to the normal function of the immune system. But that does not mean that you should therefore take high-dose vitamin D supplements as a preventive measure and without medical supervision.
Vitamin D is the generic term for a group of fat-soluble vitamins, the calciferols. Its best-known function is to participate in bone metabolism. According to the Robert Koch Institute (RKI), connections between vitamin D supply and chronic diseases are suspected, but have not yet been proven.
Sufficient sunlight fills memory
Unlike other vitamins, the body can produce vitamin D itself – through sunlight, or more precisely UV-B radiation of certain wavelengths. It is necessary to stay outdoors, because the UV-B components cannot penetrate through window panes. Diet – for example with fatty sea fish, offal, mushrooms or eggs – only contributes a relatively small proportion of the vitamin D supply.
Due to the geographical location, vitamin D formation in Central Europe is only possible in the summer months, i.e. from March to October, according to the RKI. During this time, however, the body is not only able to meet the acute need, but also to build up vitamin D reserves in fat and muscle tissue for the winter months.
This storage capacity also causes the dangers associated with careless intake of vitamin D supplements: The DGE experts warnthat a persistent overdose of vitamin D preparations can lead to side effects such as kidney stones, kidney calcifications and disorders of the cardiovascular system.
Overdosing is possible
Acute poisoning with vitamin D is also possible, according to the RKI: Excessively high intake leads to increased calcium levels in the body, which can lead to nausea, loss of appetite, stomach cramps, vomiting or, in severe cases, kidney damage, cardiac arrhythmias, unconsciousness and death.
For medical reasons, however, after an appropriate diagnosis, higher vitamin D intake levels may be useful in individual cases. According to the DGE, this applies in particular to those who can hardly or not at all be outdoors or only do so with their bodies completely covered. Even people with dark skin color produce comparatively little vitamin D due to the high melanin content of their skin.