Co-test warns: vitamin D supplements are not necessary

• The ko-Test magazine tested 21 vitamin D supplements, including 16 nutritional supplements
• The result: the drugs cut well, but the supplements fall through
• ko-test explains why supplements are usually superfluous

Vitamin D: supplements fail the test

During the cold season, as the days get shorter and darker, many people resort to vitamin D supplements. They want to compensate for the effects of lack of sun. The body can produce vitamin D itself, but needs the help of the sun.

The ko-Test magazine has therefore examined 21 preparations for sale in pharmacies or drugstores. Five of them are drugs and 16 others are nutritional supplements. The result shows that the drugs are useful – they were scored in the test with the ratings "good" to "very good". Of the supplements, ten received only the rating "Sufficient".

The testers conclude that vitamin D should only be taken as a medicine, but only in consultation with a doctor.

The body produces and stores vitamin D.

Suppliers can be completely exempt from their point of view. A healthy person produces enough vitamin D and stores it in the body, so that enough remains during the dark season. There is no danger of deficiency. The addition of vitamin D is only recommended in newborns to prevent rickets.

In healthy adults, vitamin D has no preventive effect. On the contrary, too much vitamin D alone can interfere with calcium metabolism and bone health and can cause kidney damage.

Therefore, some "ko-tests" warn that they contain much more than the specified maximum amount of 20 g. This was the case for Abbey and Tetesept products.

So the conclusion: If there is no medical need, leave fingers with vitamin D supplements. At best, they are useless and in the worst case, harmful.

Why does a person need vitamin D?

One thing is certain: a true vitamin D deficiency is actually harmful for health. But this is not the case with most people in Germany.

Vitamin D is the precursor of a vital hormone, says Professor Helmut Schatz of the Board of Directors of the German Society of Endocrinology (DGE). This is especially important for bone health, but it also affects the functioning of the muscles. Unlike other vitamins, humans only absorb a small portion of vitamin D through their diet – for example, compared to fatty sea fish.

80 to 90 percent form the body in the skin itself, using sunlight.

Now, Germany is not just bathed in sunshine. As a result, more and more people apparently believe they are suffering from a vitamin D deficiency. On their own, pharmacies have sold vitamin D supplements in 2017 for an amount of about $ 177 million. ; euro. This was calculated by the company IQVIA, which monitors the pharmaceutical market.

When do you talk about a lack of vitamin D?

Birgit Niemann of the Federal Institute for Risk Assessment (BfR) explains that we only talk about a disability when people have symptoms and are therefore sick. Symptoms of generalized deficiency were found for example in the iodine. Since the 1980s, the use of iodized salt has been widely recommended in Germany. "This is not the case with vitamin D," says Niemann. "We share the opinion that there is a vitamin D deficiency nationwide in Germany, but certainly not."

The BfR does not just want to know if there is something missing from the population, it also wants to know how people are optimally cared for. "And there is still room for a lot of vitamins," says Niemann. Vitamin D is one of them.

Which values ​​are supposed to be deficient?

According to the Robert Koch Institute, more than half of adults in Germany do not reach the optimal serum concentration of 50 nanomoles per liter (nmol / L) or 20 nanograms per milliliter (ng / mL). Do they all have a shortage? "No," said Niemann. "But they may run the risk of being under-supplied."

Because the risk of under-supply is always when the serum concentration is lower than the optimal value. Physicians speak of a disability only when the value is much lower: 10 ng / ml for a moderate impairment and 5 ng / ml for a severe impairment. Both are relatively rare, says Schatz.

Patients at higher risk of vitamin D are at higher risk, as are a few others: those who do not leave the house at all or are only veiled, people over 65 years old, and people who are dark skin. In these groups, a prophylactic dose of vitamin D is considered, says Schatz.

What is a vitamin D deficiency for your health?

But also, under-provisioning does not look like something you would like to have. But what does this mean concretely? "It's one of the fundamentals of the problem," says Schatz. "We do not know." In many studies, scientists have tried to determine whether people with low vitamin D levels died earlier if they were more likely to develop cancer or have a heart attack.

Several studies have also highlighted a link between respiratory and rheumatic diseases or diabetes and a low concentration of vitamin D in the blood. "But what is the question here: does the low level of vitamin D increase the risk of rheumatism, for example, or is it the opposite: does the disease affect the level of vitamin D? "

So you can increase its vitamin D value without pills

If you really want to know if he has enough supplies, the Stiftung Warentest will submit a blood test to the family doctor. If the examiner sees no reason, the patient has to pay around 20 euros himself. The audit is not part of a normal audit.

And anyone who thinks he can not make ends meet without food supplements can swallow such tablets at his expense, says Schatz. Dosages of 800 to 1000 international units (I.E.) at least do not harm the body. A person without a medical reason takes more than 4000 I.E. to himself, but can suffer for example the kidney.

And then, there is the natural way to fill up with vitamin D: the sun. Those who want to contribute to an optimal diet of their body must present themselves every day in front of the door. "You do not have to spend half of the day in the sun," Niemann says. "25 minutes a day." About a third of the body should be exposed to the sun.

"As a rule, we say: half the time needed for a sunburn"add a treasure. You do not have to worry about skin that gets too little vitamin D in the winter. "All those who stop regularly in the summer will fill their warehouses so well that they will be able to spend the winter." The walks are worthwhile even in winter. Because even if the sky is overcast, vitamin D is still formed in the skin.