Vitamin D is an essential molecule for the body.
It is considered a pro-hormone, and exerts various metabolic functions:
- Increased bone mineralization.
- Increased renal calcium reabsorption.
- Increased intestinal absorption of phosphorus.
- Support of the immune system.
- Differentiation of some cell lines.
- Contribution to some neuromuscular functions.
The molecular structure of vitamin D can be of five different types: D1 (ergocalciferol + lumisterol), D2 (ergocalciferol), D3 (cholecalciferol), D4 (dihydroergocalciferol) and D5 (sitocalciferol).
Needs and Contributing Foods
Il need for vitamin D it is complied with above all by the endogenous synthesis that takes place in the skin; this requires exposure to intense UV rays (the summer ones) and the substrate dehydrocholesterol. Secondly, the demand for vitamin D is compensated by the diet.
Soluble in fats (fat-soluble, such as vitamin A, vitamin E and vitamin K), vitamin D is present mainly in foods of animal origin, with some small exceptions.
Le most important nutritional sources of vitamin D are: fishery products (fatty fish), fish liver, fish liver oil, eggs (especially yolk), butter and fortified foods (eg milk).
Recently the presence of vitamin D in mushrooms; below, we will try to understand if the content in question is actually relevant from a nutritional point of view.
WARNING! Vitamin D contained in food is mainly in the form of cholecalciferol or D3. This - after following the digestion, absorption and entry into the circulation typical of fats - is transported to specific districts, where it will undergo various types of enzymatic catalysts.
NB: µg means micrograms.
|Cod liver oil||Salmon and Herring||eggs||Butter||Liver
|Vitamin D quantity
Table 1: Vitamin D content in the main food sources of animal origin.
Vitamin D in Mushrooms
As can be seen from the table below, mushrooms can be a relevant source of vitamin D.
These foods can effectively replace the liver of land animals (beef, pork, lamb, chicken, etc.), eggs, butter and fatty cheeses.
However, not all mushrooms contain the same amount of vitamin D. Among the examples reported are the boletus, the morel, the ovule, the chanterelle and the honeycomb; the champignon (also called champignon or Portobello) is not negligible but not particularly rich.
|Vitamin D quantity
Table 2: Vitamin D content in some mushrooms.
NB: Amounts equal to 0,00µg could be the result of a lack of detection, or of the unavailability of the requested value.
How Much Vitamin D?
The dietary needs of vitamin D shown in the table also take into consideration the needs of people at risk, that is, those who are limitedly exposed to sunlight or who for various reasons risk deficiency.
|Age and / or Physiological Condition||Need|
|Children 1-3 years||10μg|
|Children 4-10 years||0-10 µg|
|Girls and boys 11-17 years old||0-15 µg|
Table 3: Vitamin D requirement
The population of your country takes in about 2,00µg of vitamin D per day. This quantity seems sufficient to prevent deficiency, since endogenous synthesis alone (in the skin), in conditions of adequate sun exposure, should be sufficient (especially in adults).
The most accurate method for estimating nutrition and lifestyle adequacy is the detection of 25-hydroxyvitamin-D (25-OH-D) in the blood plasma, which should remain in the range of 10-40ng / ml ( nanograms per milliliter).
NB: one nanogram corresponds to 0,001µg.
Keep in mind that in the absence of adequate (long-term) sun exposure this plasma concentration can drop as low as 6-8ng / ml. On the other hand, after prolonged and significant intensity exposures, it can go up to 80ng / ml.
Fortunately, vitamin D can be stored in the liver; this reserve guarantees the human being to be able to draw on stocks structured during the summer period throughout the winter.
Mushrooms Against Deficiency
By making an arithmetic calculation of the vitamin D content in the richest mushrooms (porcino, morel, ovule, chanterelle and honey), we can define that these bring an average of 2,4µg / 100g of edible part.
If we were to consider mushrooms as the only source of vitamin D, we could estimate that the amount necessary to cover the safety level of males and females aged 4 and over (pregnant and nursing mothers included) is equal to 625g / day.
This is far too high a quantity and not always advisable.
It should be borne in mind that all mushrooms contain a toxic principle, including those called "edible", even if in harmless quantities or with negligible poisonous potential.
Furthermore, mushrooms are also foods subject to the accumulation of environmental contaminants. In particular, those that are wild or cultivated / harvested on the margins (or inside) of agricultural fields exploited with the conventional method (pesticides, herbicides, etc.).
These two aspects suggest not to abuse them and take on even more relevance in the nutrition of the pregnant woman and the nurse, to whom I would suggest avoiding them or not exceeding a maximum limit of 1-2 portions of cooked mushrooms (100-150g weighed raw) each week.
Ultimately, mushrooms are a decent source of vitamin D, but they cannot fulfill the role of the sole source. Alternating with fatty fish and eggs can be an excellent solution.
This conclusion must be understood especially by the vegan community which has recently been focusing much of its attention on mushrooms, considering them a solution to the risk of vitamin D deficiency.
Even for vegans "mushrooms yes, but don't overdo it!"; being able to choose, it is advisable to focus more on the sun exposure of the summer period.