Mythos-Wonder-Drug Vitamin D Supplements in the Test: Stiftung Warentest Warns Against False Purchases Updated: by Joachim Vonderthann :newstime Vitamin D: the Mythos-Wonder-Drug (23. January) Video clip · 01:42 Min · From 12 Our body can produce vitamin D itself through sunlight. Since this is rare…
Mythos-Wonder-Drug
Vitamin D Supplements in the Test: Stiftung Warentest Warns Against False Purchases
Updated:
by Joachim Vonderthann
:newstime
Vitamin D: the Mythos-Wonder-Drug (23. January)
Video clip · 01:42 Min · From 12
Our body can produce vitamin D itself through sunlight. Since this is rare in winter, many people take supplements. However, Stiftung Warentest recommends only two products.
The most important thing at a glance
- Stiftung Warentest has examined vitamin D supplements. - Many are overdosed and can cause health damage to certain population groups. - Only two products are considered suitable by the testers: In the dark months of the year with vitamin D supplements: Who is on the move in social media gets the impression: "Many people do that."But the means are not without risks. Those who want to take them should pay attention to the dosage. Most of them are actually too highly dosed, as an investigation by the magazine Stiftung Warentest shows (Issue 1/2026). What is to be noted and which products are recommended? Why does our body need vitamin D at all? Vitamin D is needed by our body among other things for the stability of the bones, as explained by Daniela Krehl, nutrition expert of the Verbraucherzentrale Bayern. Because vitamin D ensures that the body can take up calcium from the digestive tract and build it into the bones. In addition, it is important for muscle function, hormone metabolism, and immune defense. Where does the body get vitamin D? There are foodstuffs that supply us with vitamin D, such as fatty fish like salmon and mackerel, plant oils, and dairy products. "But you can't cover the demand with that," says Prof. Johannes Wechsler, President of the Federal Association of German Nutritionists: Only about ten percent of the demand is taken up through food. The rest is produced by the body itself, for which it needs sunlight, which hits the skin. How much vitamin D a body can produce in this way exactly depends on many factors: season, latitude, time of day, and skin type - and also whether we have applied sunscreen. Various professional associations have developed a recommendation for how much solar radiation is sensible to produce sufficient vitamin D. According to this, it is sufficient to expose face, hands, and arms two to three times a week uncovered and without sun protection to the sun. And that for half the time in which one would otherwise get a sunburn unprotected. By the way: From the sun we store in the summer, we still have something in the winter. The body stores vitamin D in fatty and muscular tissue. Who needs additional vitamin D? According to data from the Robert Koch Institute (RKI), 44 percent of adults in Germany are well supplied with vitamin D. Taking additional vitamin-D supplements brings them nothing. Stiftung Warentest refers to the fact that studies have not been able to sufficiently prove that vitamin-D supplements protect against cancer and cardiovascular diseases. However, there are groups that have an increased risk of not being sufficiently supplied with vitamin D: For example, people who get little sunlight. "For example, bedridden people or people who completely cover themselves," says Daniela Krehl.
Further risk groups are according to the Stiftung Warentest: - Over-65-year-olds - People with obesity - People with dark skin color - People with certain diseases, such as chronic diseases of the parathyroid gland, kidney or gastrointestinal tract - They can benefit from taking vitamin D preparations - especially between October and March. Only a blood analysis brings clarity How well the body is actually supplied with vitamin D can only be determined by a blood analysis. Those who are unsure can address the topic to their family doctor or general practitioner. If there is suspicion of a deficiency, the health insurance company covers the costs for a blood test. Otherwise, one has to pay out of pocket, which according to Stiftung Warentest costs around 20 to 50 euros. Tip: The end of winter is not a good time to let oneself be measured. Then the stores are empty and the values are less meaningful. Also in the news: Which vitamin D products cut well? Who wants to take a vitamin D preparation should - especially when it happens on their own initiative - pay attention to a low dose. At most 20 micrograms or 800 international units (i.E.) of vitamin D should be taken per day through dietary supplements, advises the Federal Institute for Risk Assessment (BfR). Of the 25 dietary supplements that Stiftung Warentest has checked, most are over-dosed. Five even rattle with the verdict 'not suitable' because they contain so much vitamin D that kidney damage threatens if taken long-term. Only two products are rated as suitable by the testers: - the tablets 'Vitamin D compact' from GSE (daily dose: 200 i.E.) - the juice 'Vital Vitamin D' from Rotkäppchen (daily dose: 400 i.E.) And Stiftung Warentest has another tip: So-called depot preparations, which one swallows for example only once a week, are viewed critically by the testers because errors in taking can occur quickly. If one swallows them by mistake more often than once a week, overdosing threatens. In addition: Very high single doses can, as studies show, increase the risk of falls and bone fractures in the elderly. Further tests by Stiftung Warentest: Sources used: News agency dpa Stiftung Warentest: 'Often swallowed, not always sensible'
