- The co-Test magazine has tested 21 vitamin D supplements, including 16 nutritional supplements
- The result: medicines are cut well, but all supplements fall
- the co-test explains why supplements are usually useless
Vitamin D: Supplements fail the test
In winter, when the day gets shorter and gets darker, many people use vitamin D supplements. They want to compensate for the effects of lack of sunlight. The body can produce its own vitamin D, but it needs the help of the sun.
Co-Test magazine has seen 21 preparations sold at pharmacies or drug stores. Five of them are medicines and 16 are nutritional supplements. The results showed that the drugs were useful – they got scores on the test with "good" to "very good" scores. From supplements, ten only receive the value "Enough"
The examiners came to the conclusion that vitamin D must only be taken in the form of drugs, but only in consultation with a doctor.
The body produces and stores vitamin D.
Suppliers can be completely eliminated from their point of view. Healthy people produce enough vitamin D and store it in the body, so even in the dark season is enough. There is no danger of deficiency. Only in newborns is the addition of recommended vitamin D to prevent rickets.
In healthy adults, vitamin D does not have a preventive effect. Conversely: too much vitamin D, taken alone, damages calcium metabolism and bone health and can cause kidney damage.
Therefore some "co-tests" warn that they contain more than the maximum number of 20 g specified. This is the case for Abbey products and dropsepts.
So, the conclusion: If there are no medical needs, let the fingers supplement vitamin D. At best they are useless and in the worst case dangerous.
Why does someone need vitamin D?
One thing is certain: vitamin D deficiency is actually harmful to health. But that doesn't happen to most people in Germany.
Vitamin D is a precursor of vital hormones, explained Prof. Helmut Schatz of the German Society for Endocrinology (DGE) council. This is very important for bone health, but also affects muscle function. Unlike other vitamins, humans only absorb a small portion of vitamin D through their food – for example, fatty sea fish.
80 to 90 percent form the body on the skin itself, using sunlight.
Now Germany is not only sunbathing. Therefore, more and more people seem to believe that they suffer from vitamin D deficiency. The pharmacy itself sells vitamin D supplements in 2017 for around € 177 million. This was calculated by the IQVIA company, which monitors the pharmaceutical market.
When did you talk about vitamin D deficiency?
Birgit Niemann from the Federal Institute for Risk Assessment (BfR) explained that we only talk about deficiencies when people have symptoms and are therefore sick. Extensive deficiency symptoms are usually found in iodine, for example. Since the 1980s, the use of iodine-iodized salt has been widely recommended in Germany. "That doesn't happen with vitamin D," stresses Niemann. "We share the view that there is a national vitamin D deficiency in Germany, certainly not."
BfR is not only interested in whether the population lacks something – the institute also wants to know how optimal society is. "And there's still room for lots of vitamins," Niemann said. Vitamin D is one of them.
Which values are considered lacking?
According to the Robert Koch Institute, more than half of adults in Germany do not achieve optimal serum concentrations of 50 nanomoles per liter (nmol / L) or 20 nanograms per milliliter (ng / ml). Are they all lacking? "No," said Niemann. "But they could be at risk of deficiencies."
Because the risk of supply shortages is always when the serum concentration is below the optimal value. However, doctors do not talk about deficiencies until their values are much lower – 10 ng / ml for moderate and 5 ng / ml for severe deficiency. Both are relatively rare, Schatz said.
Patients who are at high risk of vitamin D are at greater risk, as well as some others: people who do not leave home at all, or those who only veil, parents over 65 years of age, and people with dark skin. In these groups, vitamin D prophylactic doses were considered, Schatz said.
What does vitamin D deficiency mean for your health?
But flaws also don't sound like something you want to have. But what does that mean concretely? "That's one of the core problems," Schatz said. "We don't know." In many studies, scientists have tried to find out whether people with low vitamin D levels die early, if they are more likely to develop cancer or have a heart attack.
Some studies also found an association between respiratory disease and rheumatism or diabetes and low vitamin D concentrations in the blood. "But what's the question here: whether low vitamin D levels now increase the risk, for example, rheumatism, or is it the other way around: does disease affect vitamin D levels?"
So you can increase the value of vitamin D without a pill
If you really want to know if he has enough supplies, the Stiftung Warentest will give you a blood test about your family doctor. If the examiner does not see any reason, the patient must pay around 20 euros himself. The check is not part of the normal check.
And anyone who thinks that he can't make ends meet without food supplements can swallow such pills at his own expense, Schatz said. The dose of 800 to 1000 international units (I.E.) at least does not harm the body. Does someone without medical reasons need more than 4000 I.E. for himself, but can suffer for example kidney.
And then there are natural ways to replenish vitamin D: the sun. Those who want to contribute to their body's optimal supply, must go every day before the door. "You don't have to spend half a day in the sun," Niemann said. "25 minutes every day." About one third of the body must be exposed to sunlight.
"As a rule of thumb we say: half the time for sunburn"add treasure. You don't need to worry about skin that gets too little vitamin D in the winter. "Those who spend a short amount of time in summer regularly fill their warehouse well so they can get through the winter." Walking is very valuable even in winter. Because even if the sky is closed, vitamin D still forms on the skin.