Since the onset of the coronary pandemic, recommendations for vitamin D supplements have been heard again. And if given in appropriate doses, these drugs are not harmful either. According to the Robert Koch Institute, people living in Central Europe replenish their vitamin D stores between March and October – this is where the sun has the most power. This not only covers acute needs, but also creates reserves that will take us through the winter months.
Technical shortcomings in studies
Studies from Europe or the US, which are being critically experienced by experts, are repeatedly used to advertise vitamin D intake to protect against (serious) coronavirus diseases. Studies have shown that vitamin D supplementation has a positive effect, that patients in intensive care units often suffer from vitamin D deficiency, or that people with good vitamin D levels do not see it at all. The technical shortcomings of the study are criticized: For example, because the patient’s vitamin D status was not known before the disease, the control or comparison group was not appropriate or previous diseases such as diabetes or obesity had a negative effect on vitamin D mirrors were neglected.
Previous diseases neglected in the control group
One popular study is that of the Reina Sofia Hospital in Madrid: of the 50 patients with Covid 19 who received vitamin D, only one ended up in the intensive care unit. In the control group – without vitamin D – it was 50 percent. It sounds good at first, but experts criticize the fact that groups of patients are not selected immediately. From the beginning, there were significantly more people in the control group with pre-existing conditions such as diabetes or high blood pressure. Diseases we already know can lead to a severe course of Corona. Experts are therefore not surprised that they then end up in the intensive care unit. In contrast, the study cannot draw a positive effect on vitamin D administration.
“If you put the (relatively) healthy in the vitamin D group, and the (relatively) sick in the control group, then it’s clear in advance what will result from that.” Martin Smollich, pharmacologist and professor at the Institute of Nutritional Medicine of the University Medical Center Schleswig-Holstein in Lübeck
There is no clear cause-and-effect relationship
According to the findings of the German Nutritional Society (DGE), in which experts have conducted dozens of studies, there is no reliable evidence of corona protection with vitamin D preparations. A link can be assumed, but the results are not sufficient to show a clear cause-and-effect relationship. According to the Federal Institute for Risk Assessment (BfR), the fact that vitamin D contributes to the functioning of the immune system is scientifically indisputable. It is actually very important. But that doesn’t mean you have to take excessive (and perhaps too high) supplements preventively.
Notes, but no evidence
The Robert Koch Institute also points out on its website that there are still several clinical studies on the association between vitamin D and the severe course of Covid-19. The causality has not yet been proven. However, there are indications of an increased risk of a severe course of vitamin D deficiency, as well as the fact that fewer people should be treated in intensive care after vitamin D supplementation. There is also evidence that infection subsides more rapidly with vitamin D deficiency if vitamin D deficiency is previously identified. , it was also pointed out that there is no recommendation for preventive intake of vitamin D. However, if there is a deficiency, it can and should be compensated. Especially if you belong to a risk group.
Covid-19 Consequence of vitamin D deficiency, not cause
What Martin Smollich of Schleswig-Holstein University Hospital also criticizes is that low vitamin D levels are often used as a cause of Covid 19 disease, but not as a consequence. Because the disease weakens the immune system and causes a drastic drop in vitamin D levels in the short term in the case of an acute severe infection.
Previous illnesses have led to a severe course of Covid-19
Thus, causality is often used here that is not so easy to determine. Studies have only found that vitamin D levels were at the same time quite low in patients with severe courses. But that is not the cause. There is not necessarily a direct connection. Vitamin D deficiency may simply mean that there are other existing conditions that have lowered the level, which in turn can lead to a severe course of Covid-19. Or that vitamin D levels that were low from the start led to other previous illnesses. Because vitamin D is very important for the functioning of the immune system.
Vitamin D deficiency is common in the elderly
Older people tend to have a higher-than-average vitamin D deficiency, as there are other diseases in old age that cause levels to decline, while vitamin D production declines with age. In the GDR’s podcast for the crown, virologist Sandra Ciesek points out that vitamin D deficiency is more common in people who are rarely outdoors. This is especially true for people with reduced mobility, the chronically ill and those in need of care – often the elderly.
Side effects of too much vitamin D.
Then preparations can help, dietary supplements. However, the dosage should definitely be discussed with your doctor. Because too much vitamin D can lead to unpleasant side effects such as kidney stones, kidney calcification and cardiovascular disorders in the long run, as DGE experts warn.
Walk enough in the summer
Unlike “real” vitamins, only ten to twenty percent of vitamin D, which is only a precursor to hormones, is absorbed by food. Few foods contain enough vitamin D to meet their needs. Therefore, vitamin D stores are best replenished by the sun. Thanks to UVB radiation, the liver and kidneys make a vital vitamin. Basically, a five to 25 minute walk in the fresh air is enough in the summer to get enough vitamin D. Simply expose your face, hands, feet and hands to the sun every day. Then we can go through the gloomy winter months.