La magia dei funghi - La vitamina D
Vitamin D, essential for humans, is known in its two most important forms:
- vitamin D2
- vitamin D3
Both have very similar biological activity. The main difference is that vitamin D2 is of plant origin and is naturally present in mushrooms, while D3 is synthesized in animal organisms.
Vitamin D group vitamins can be produced by the body in sufficient quantities when the skin is exposed to ultraviolet radiation from the sun. If sun exposure is limited, this deficiency must be compensated with targeted dietary intake.
Mushrooms are the only non-animal food product with a significant amount of bioavailable vitamin D. Therefore, they could be used as a primary and relevant source of vitamin D for vegan and vegetarian diets.
Almost all edible mushroom species, when exposed to sunlight, generate vitamin D. Some even produce so much that they can be considered a good alternative to liver, eggs, and dairy products of animal origin.
However, if we were to consider mushrooms as the only source of vitamin D2, the quantity to be consumed to reach the daily requirement for an adult would be decidedly too high and therefore inadvisable.
Logically, mushrooms do not all contain the same amount of vitamin D2.
A typical example of wild mushrooms rich in vitamin D includes:
- porcini mushrooms (Boletus edulis and related group),
- Saint George’s mushroom (Calocybe gambosa),
- Caesar’s mushroom (Amanita caesarea),
- chanterelles (Cantharellus cibarius), and
- honey fungus (Armillaria mellea).
The situation is different when mushrooms are cultivated. Species such as:
- champignon (Agaricus bisporus),
- shiitake (Lentinus edodes),
- oyster mushroom (Pleurotus ostreatus)
Although they produce vitamin D2, are not particularly rich in it when grown in cultivation (they are cultivated in environments with controlled temperature and humidity).
Recent studies have shown that mushrooms of the same species that grow wild in nature (Agaricus bisporus, Lentinus edodes, and Pleurotus ostreatus), being exposed to solar radiation and UV rays during their growth and development phase, generate higher amounts of vitamin D2.
