Vitamin D promotes the absorption of calcium from the gastrointestinal tract and bones’ hardening. It affects muscle strength, regulates calcium and phosphate metabolism, and is also involved in other body metabolic processes. In humans, vitamin D is produced in the skin under sunlight’s influence. Unlike the body’s own production, vitamin D in food makes up only a relatively small share of the vitamin D supply. The German Nutrition Society (DGE) claims that a daily dose of 20 micrograms of vitamin D is sufficient for children, adolescents, and adults.
It is not recommended to enrich foods with vitamin D. The focus is on the body’s own vitamin D production and thus on the recommendation for the production and storage of vitamin D by exposing the skin to sunlight. The body’s own production varies from person to person and depends on other factors, such as latitude and climatic conditions. It is recommended that you expose yourself to the sun for a total of about 5 to 25 minutes a day with your face uncovered and most of your arms and legs. Intake of vitamin D supplements is recommended only if the targeted improvement in supply, especially for risk groups, cannot be achieved either through diet or through creating the body’s own vitamin D during sun exposure.
Vitamin D, our body can produce if the skin gets enough sunlight. On the other hand, the need to satisfy vitamin D with food is relatively small: only a few foods contain significant amounts of vitamin D. The high content of vitamin D in cod liver oil is known to almost everyone.
Vitamin D – food on the menu
The estimated need for vitamin D in children aged one year, adolescents, and adults is 20 micrograms per day. This makes it possible to achieve a concentration of 25-OH-vitamin D (a form of vitamin D storage) in the blood that is considered optimal for healthy bones – namely at least 50 nmol / l (= 20 ng/ml).
With sufficient sun exposure, the recommended daily requirement of vitamin D (and consequently, the desired concentration of 25-OH vitamin D in the serum) can be largely covered by self-production: the body then produces 80 to 90 percent of the required amount of vitamin D in the skin. A significant amount of vitamin D (e.g., oily fish like herring and mackerel) makes up the (small) residue.
This process becomes problematic when the skin is not exposed to a sufficient amount of sun or when the sun is too weak for its own production of vitamins, e.g., in the winter months. The food usually on our menu does not contain a lot of vitamin D, about two to four micrograms a day (even less in children). This means: To get the recommended dose of 20 micrograms a day, you would have to, for example, eat two kilograms of Emmentaler.
In the summer months, we should not avoid going out regularly if we do not want to suffer from a lack of vitamin D. Those who sunbathe in the summer also have a full supply of vitamin D.
Also, experts recommend regular consumption of foods with vitamin D – even if the diet is only a small part of the needs. But first, you need to know: Which foods contain vitamin D, and in what amounts?
Vitamin D in food but which one?
Cod liver oil was once considered a premium food rich in vitamin D. It is a fatty oil extracted from the liver and kidneys of this marine inhabitant. Cod liver oil contains a relatively large amount of sun vitamin, but it does not taste perfect.
Fortunately, there are alternatives – though not many. First of all, foods of animal origin contain the appropriate vitamin D. But some plant-based foods contain vitamin D, as you can see in the table below:
|FOOD||Vitamin D content in micrograms per 100 grams|
|Drinking milk, 3.5% fat||0.1|
|Vegetable cream cheese||0.6|
|Quark (20/40% fat in dry matter)||0,1 / 0,2|
|Processed cheese (45% fat in dry matter)||3.1|
|Fish, sea animals|
|Edible snout, porcini, cheese||3.1|
How do you make a meal to get about 20 micrograms of vitamin D a day?
Here is an example after a meal:
100 grams of eel
80 to 90 grams of herring
4 egg yolks (like an omelet)
Anyone who eats food of animal origin can cover their needs. Vegans, who completely give up animal products, find it difficult to achieve a sufficient vitamin D dose through their diet. Fruits and vegetables contain minimal amounts of this vitamin. Besides, plant foods contain only vitamin D2 – less effective than vitamin D3. Sometimes, it can also help vegans take a vitamin D supplement (in consultation with a doctor).
Vitamin D: Instructions for food storage and preparation
Vitamin D is relatively thermally stable and is retained even during cooking at temperatures up to 180 degrees Celsius.
Are Vitamin D Supplements Necessary and Useful?
As mentioned above, there is almost no food with a lot of vitamin D. Therefore, and it is difficult to meet the requirements only with foods containing vitamin D if there is not enough sunlight. In this case, it is often useful to add vitamin D through supplements.
However, high doses of vitamin D can sometimes lead to serious health side effects. Therefore, it is advisable for the doctor to first check the supply of vitamin D (measuring 25-OH vitamin D in the blood) before resorting to vitamin D supplements. If you really have a deficiency, your doctor will recommend an appropriate vitamin D dose depending on the degree of deficiency.
Questions and answers about vitamin D.
What is vitamin D and why does the body need vitamin D?
How much vitamin D does a person need and how can the amount of vitamin D be determined?
In contrast, vitamin D intake through a regular diet makes up only a relatively small percentage (10 to 20 percent) of the vitamin D supply. Serum 25-hydroxyvitamin D concentration is used as a marker to assess supply because it reflects vitamin D supply through diet and own production of vitamin D in the body. Vitamin D deficiency is reported at serum concentrations of the marker 25-hydroxyvitamin-D below 30 nanomoles per liter of serum (30 nmol / l). This corresponds to 12 nanograms per milliliter of serum (12 ng / ml). A good supply of vitamin D is when the concentration of this blood marker is at least 50 nanomoles per liter of serum. This corresponds to 20 nanograms per milliliter. If the body does not produce its own vitamin D, this concentration is achieved by ingesting 20 micrograms of vitamin D per day.
What is the storage capacity of vitamin D in the body?
What are the consequences of vitamin D deficiency?
What are the risk groups for vitamin D deficiency?
Is the body’s own production of vitamin D sufficient in old age?
Do you need to go to the solarium to improve your vitamin D supply?
According to the recommendation of the Federal Institute for Radiation Protection, especially children and young people should not go to the solarium. According to the Federal Institute for Radiation Protection, visits to solariums can increase skin cancer risk.
Is an excessive amount of vitamin D possible by one’s own synthesis in the body?
What to look for in case of frequent sun exposure?
Is it necessary to use foods enriched with vitamin D?
Does an excessive amount of vitamin D have health consequences?
In case of additional intake of vitamin D through vitamin D preparations, it must be taken into account that the European Food Safety Authority (EFSA) has an acceptable total daily intake of 100 micrograms of vitamin D for adults and children 11 years and older and for children up to 10 years. Of life obtained from 50 micrograms of vitamin D., These tolerable total daily intakes refer to vitamin D intake from food (including vitamin D supplements and fortified foods).
Regular daily intake of more than 100 micrograms of vitamin D, which is currently possible with normal eating habits only with excessive vitamin D supplements, can cause side effects such as kidney stones or kidney calcification. However, for medical reasons, higher amounts of vitamin D may be medically indicated.