John Myers
If mushrooms are exposed to sunlight, they form vitamin D and thus become a valuable source of vitamin D. However, since mushrooms also thrive without sunlight, many cultivated mushrooms are grown in dark plants and then of course do not provide any vitamin D. However, you can “reload” mushrooms that have already been harvested with vitamin D.
Vitamin D in mushrooms
Vitamin D is an essential vitamin. It regulates the immune system, reduces inflammation, elevates mood, and prevents many chronic diseases.
Unfortunately, there are only a few that contain relevant amounts of vitamin D. Liver, herring, and eel would be good options. Anyone who lives vegan or does not like to eat these foods regularly for other reasons can fall back on the sun. Vitamin D is formed in the skin with the help of sunlight.
But that only works in Central Europe in summer. This is why a few food shortages are so widespread. Because even in summer, many people do not manage to go out in the sun regularly to replenish their vitamin D stores – especially since vitamin D is only formed in the skin if sun creams with high sun protection factors are not used.
Dietary supplements with vitamin D are an alternative. However, many people would prefer to cover their need for vital substances in a natural way, i.e. with food. But what to do if liver, fish, and co are out of the question? The solution is: to eat mushrooms!
Put mushrooms in the sun and enrich them with vitamin D
Mushrooms can be an excellent vegan source of vitamin D, but only if they have been able to grow under daylight. Only then can they – just like humans – produce vitamin D.
It is practical that mushrooms can still produce vitamin D after they have been harvested. This means that you can lay the purchased mushrooms in the sun and in this way multiply the vitamin D content of the mushrooms.
Almost all mushrooms that are commercially available are suitable. For example, you can use button mushrooms or shiitake mushrooms, but also many other types of mushrooms.
Apparently, the vitamin D fortification should even work if you put mushrooms in the sun that were already cut and dried in.
As soon as the mushrooms have been able to accumulate vitamin D in the sun, the vitamin D in them remains stable for months. Such mushrooms are therefore ideal for storing vitamin D.
In the future, you can not only use the summer (May to September) to replenish your own vitamin D supplies by staying outside as often as possible and soaking up the sun. You can also dry mushrooms in the sun in the summer and save them for the winter. In the low-light season, you are then well supplied with natural and vegan vitamin D.
Mushrooms provide vitamin D2
Mushrooms naturally contain the vitamin D precursor ergosterol. If you expose them to UVB radiation, ergocalciferol, also known as vitamin D2, is formed.
The question often arises as to whether vitamin D2 is just as good as vitamin D3. In the New England Journal of Medicine, vitamin D expert Dr. Michael F. Holick published a detailed article that, among other things, compared the metabolic pathways of vitamin D2 with those of vitamin D3.
Holick wrote that the body’s enzymes can easily convert both types of vitamins into active vitamin D. A study from 2013 (published in Dermatoendocrinology) also showed that vitamin D2 from mushrooms can raise the vitamin D level just as well as vitamin D3.
The only advantage of vitamin D3 is that it stays in the blood longer than vitamin D2. While vitamin D2 is only available for a few days, vitamin D3 remains for a few weeks or months.
However, if you are taking a supplement several times a week anyway, then you can also meet your vitamin D needs with vitamin D2 and it doesn’t matter whether you take vitamin D3 (in capsules) or vitamin D2 (with the dried mushrooms).
Apart from that, with dried mushrooms, you not only get vitamin D but also many other helpful nutrients and vital substances, such as e.g. B. beta-glucans to stimulate the immune system, ergothioneine as an antioxidant, substances that stabilize the nervous system and brain functions, and substances that have antimicrobial properties and thus relieve the immune system.
How much vitamin D do sun-dried mushrooms provide?
Officially, it is said that an adult gets along just fine with 800 IU of vitamin D per day. Yes, there is a real warning about higher doses. At the same time, however, some clinics prescribe 4,000 to 10,000 IU of vitamin D for sick people (e.g. cancer patients) in order to get well again.
Furthermore, scientists from the University of California in San Diego and Creighton University in Nebraska revealed in March 2015 that the usual vitamin D recommendations were based on nothing more than a calculation error and that the real vitamin D requirement was ten times higher, i.e. around 7,000 IE lie. The researchers published their corresponding study in the specialist journal Nutrients.
Could mushrooms actually provide such high amounts of vitamin D to meet human needs?
Paul Stamets, an advisor on an integrative medicine program at the University of Arizona Medical School, Tucson, conducted several experiments with mushrooms to clarify their vitamin D properties:
We examined three groups of organically grown shiitake mushrooms. One group was grown and dried without light. The second was grown without light but dried in the sun (with the slats pointing to the ground). The third group was identical to the second, except that we laid them out to dry with their slats facing the sun.”
The highest vitamin D values could be measured in the third group. Before drying, the mushrooms showed a vitamin D value of only 100 IU per 100 grams.
But after lying in the sun (with the slats up) for two days (6 hours a day) their vitamin D levels in the cones had risen to 46,000 IU per 100 grams. The stalks contained “only” 900 IU per 100g.
On the third day, vitamin D levels dropped, presumably due to an overdose of UV radiation, so the mushrooms should never be left in the sun for more than two days.
“When we tested our dried mushrooms again for vitamin D a year later,” says Stamets, “they still showed very significant vitamin D levels, so the sun-dried mushrooms are very suitable for making your own vitamin D.” collect” and store this in mushroom form for the winter.”
Fortify mushrooms with vitamin D in the sun
If you are now interested in drying mushrooms in the sun and enriching them with vitamin D in this way, here is a brief summary of the procedure:
- Lay the unwashed mushrooms in the sun with the slats facing up to dry.
- Mushrooms should be dried no more than 2 days and no more than 6 hours per day.
- The amounts of vitamin D created in this way remain in the mushrooms for at least a year. You can therefore dry enough mushrooms in the sun in summer and enrich them with vitamin D so that you can snack on them regularly in winter.
- Daily consumption of 2 to 15 grams (depending on need) of sun-dried shiitake mushrooms may be enough to meet daily vitamin D needs. Paul Stamets writes, “Eating a handful of these sun-dried mushrooms four times a week is enough to significantly increase or maintain your vitamin D levels at a healthy level.”
- The dried mushrooms should not be washed. They can be eaten raw or cooked/fried.
- However, if you heat them, you should also consume the liquid that is produced when frying or steaming, because not only vitamin D but also other vital substances could have dissolved in it.
