La vitamin D it is produced by our body and is present in some foods, including mushrooms. Is it enough to expose yourself to the sun and eat a lot of mushrooms to avoid a vitamin D deficiency? Let's see the myths to dispel on this very important vitamin for bone health.
What is vitamin D used for?
La vitamin D it is a fat-soluble vitamin, which can be of endogenous origin, ie produced by the body, or of exogenous origin, ie taken with food.
La vitamin D2, or ergocalceferol is of endogenous origin and is produced by the body from 7-dehydrocholesterol present on the skin following irradiation with UV rays.
La vitamin D3, or cholecalciferol is both of endogenous and exogenous origin, therefore part of it it is taken through food.
Once absorbed, vitamin D2 and vitamin D3 are activated through chemical reactions that take place in the liver and kidney. Active vitamin D is considered a real hormone involved in controlling calcium metabolism.
Vitamin D performs several functions within the body: promotes the absorption and transport of calcium and phosphate in the intestine; facilitates the reabsorption of calcium and phosphorus by the kidneys; promotes the removal of calcium from the bone to keep blood levels of this mineral stable.
La vitamin D deficiency causes demineralization of bones, resulting in rickets in children and osteomalacia in adults.
According to the LARN, the average daily requirement of vitamin D is equal to 10 μg expressed as cholecalciferol; thirty minutes of sun exposure cover a large part of the vitamin D requirement.
Much higher doses than those recommended can cause intoxication, therefore it is good not to abuse supplements that contain vitamin D: in case of intakes higher than 250 μg, nausea, hypercalcemia and calcification of the bone tissues can occur.
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Foods that contain vitamin D
La vitamin D it is contained in few foods, especially of animal origin. In particular, high concentrations of vitamin D are found in the liver oils of marine fish (about 200 μg per 100 grams of oil).
Vitamin D is also contained in some fish including herring, tuna, swordfish, trout and salmon; such foods generally contain amounts of vitamin D equal to or greater than 10 μg per 100 grams of food. Lower amounts of vitamin D are found in egg yolk.
Among the foods of plant origin, the porcini mushrooms as a source of vitamin D.. However, the quantity of vitamin D present in mushrooms is equal to or less than 2 μg per 100 g of product: such a low content therefore does not allow us to consider mushrooms a good source of vitamin D.
Therefore whoever follows a vegan or vegetarian diet could suffer from a lack of vitamin D, especially if during the summer months it is not exposed to the sun: the deficiency must be evaluated with your doctor, as well as the integration that can be carried out with fortified foods or through the administration of food supplements .
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