Can Vitamin D Requirements Be Met Through a Balanced Diet?

Vitamin D fulfills many functions in the body, for example, it is important for strong bones and supports the immune system. However, the daily requirement cannot be covered by diet alone. Vitamin D has a special status among vitamins: the body can produce it itself with the help of sunlight that hits the skin. In this way, an average of 80 to 90 percent of the vitamin D requirement in Germany is covered.

In order for the body to be able to form vitamin D from sunlight, you should spend some time outdoors every day. At least the face, hands, arms, and parts of the legs should be exposed to the sun. It is very difficult to generalize about a recommended duration. How much vitamin D the body can form with the help of the sun depends on several factors, for example, the season, the intensity of the sun’s rays, the time of day, age, and skin type. Adults should expose the above-mentioned parts of the body uncovered to the sun for between 5 and 25 minutes a day in the summer months in order to cover their vitamin D requirements. In the winter months, the sun’s rays seem to be too weak in our latitudes to produce sufficient vitamin D. However, sunburn should be avoided at all costs for health reasons.

The need for vitamin D can only be estimated. If the body does not absorb it from the sun at all, children and adults need 20 micrograms from other sources every day. However, very few foods contain vitamin D at all: it is found, for example, in fatty sea fish such as herring, salmon, or in cod liver oil. Egg yolks and dairy products as well as avocados and mushrooms also contain certain amounts of vitamin D.

However, it is not possible to cover all daily needs with food. If people are not exposed to enough sunlight, this can lead to a certain undersupply. In this country, there is rarely an actual shortage. However, more than half of the German population would need a higher level of vitamin D in the blood in order to be able to fully utilize all of the vitamin’s functions. However, the supply of vitamin D through dietary supplements should only be done on medical advice.