Vitamin D plays an important role in bone and tooth development. Find out how it is made and how to get enough of it in this health tip.
Vitamins have countless important functions in our bodies and are essential for us humans. Unlike plants, though, we can’t produce them ourselves. We need to get them from food. Vitamin D is a slight exception: a precursor for cholesterol, which is found in the skin, is converted into vitamin D with the help of UVB rays from sunlight. Because the body is involved in the production of vitamin D, it is not strictly speaking a vitamin, but a hormone.
The most important function of vitamin D in the body is its involvement in calcium absorption in the intestine. Calcium is a mineral that is needed for the formation of bones and teeth, so it’s an extremely important substance. Vitamin D helps to absorb calcium from food (for example from dairy products) in the intestine and store it in the bones. If the body doesn’t have enough vitamin D, not enough calcium will be absorbed and there is a risk of damage to the bones. Children with severe calcium deficiency can develop rickets, a disease where the bone tissue is too soft and the bones become bent as a result. In older people, osteoporosis can occur, where bones become less stable and more brittle.
The situation is a bit different in the winter. You tend to go outside less, most of your skin is covered up with clothing and the sun's rays are also much weaker than in the summer. It is estimated that 60% of the Swiss population have vitamin D deficiency in the winter. So it's worth giving it a bit of a boost by eating the right foods. Good foods are:
oily fish like wild salmon or herring
egg yolks
certain edible mushrooms like button mushrooms or chanterelles
dairy products
You can also take vitamin D drops. Both oil-based and alcohol-based solutions are available. Because it is fat-soluble, vitamin D is absorbed more readily with food. In the case of infants, the drops can be added to breast milk or cereal, or taken orally. The Federal Office of Public Health recommends that children up to the age of one, people over 60, pregnant women and chronically ill people take vitamin D supplements all year round after consulting a doctor.
Vitamin D is a fat-soluble vitamin so it can be stored in fat and muscle tissue. If too much vitamin D is ingested, only a small amount can be excreted in the urine, unlike with water-soluble vitamins. This means you should not take vitamin D supplements if you spend enough time in sunlight, eat a balanced diet and are not diagnosed with a deficiency. Too much vitamin D can even be harmful because large amounts of calcium enter the bloodstream, which can lead to vomiting and muscle weakness, and in severe cases can even result in kidney damage or cardiac arrhythmia.