The dietary supplement vitamin D is repeatedly said to have numerous positive effects on health. The vitamin is primarily necessary in the body so that calcium from the intestine can be incorporated into the bones and subsequently strengthen them. The vitamin is also involved in metabolic processes and in the formation of proteins. Vitamin D is formed with the help of sunlight, and the body produces 80 to 90 percent of what it needs itself. Spending enough time outdoors is therefore essential, but the amount of time required varies depending on the season. While it is sufficient for healthy people to be outside for five to 15 minutes in summer, the Federal Institute for Risk Assessment recommends ten to 25 minutes in winter.
The fact that vitamin D is touted as a miracle cure for numerous diseases has recently led to people taking an overdose of the vitamin through dietary supplements. A trend that can also be dangerous, experts warn. In the case of a Canadian who took an increased dose of vitamin D over a two-year period, the body developed hypercalcemia – the man had too much calcium in his blood.
overdoses are increasing
In 2022, the German poison information center reported, among other things, on 162 cases of vitamin D overdose, in 2021 there were 131. This is not what people want, say doctors. The Austrian Society for Bones and Mineral Metabolism (ÖGKM) also commented on the “hype”. If the evidence is poor, unusually high doses would be prescribed and consumed without thinking as a prophylactic or treatment for many diseases. It is said that vitamin D administration for all healthy people, regardless of age, is not advocated.
A general vitamin D substitution for all people is actually neither scientifically proven, nor is it recommended by scientific societies. For certain patients as well as for newborns, small children and other risk groups, there are clear, scientifically undisputed criteria for administering vitamin D in adequate and not extremely excessive doses. These include people in need of care, who often do not spend enough time outdoors and cannot absorb enough calcium from food.
perform a blood test
Unfavorable weather conditions and the resulting insufficient UV-B radiation, skin color and body weight can also influence the natural absorption of vitamin D. Gastrointestinal and liver diseases can also trigger a deficiency.
In order to avoid an overdose, it is advisable to have a blood test carried out by the doctor in advance to determine a possible deficiency. One speaks of a deficiency when there is a lack of vitamin D in the body over a longer period of time, but it should be borne in mind that the vitamin D level is subject to strong seasonal fluctuations.