Updated: Jul 26, 2020
Although mushrooms are classified as vegetables, technically they are not plants but part of the kingdom called fungi. However, they share some characteristics with plants. Mushrooms are very low in calories, are very low in fat and salt.
We get most of out vitamin D from sunlight (D3). However supermarkets have recently started selling mushrooms high in vitamin D². They are produced by being grown in the dark and then they are exposed to UV light for a short period. The ergosterol that mushrooms contain creates a good form of vitamin D when they exposed to this form of light.
The Hereford Dietitian's recommendation
A small portion of 100g of the mushrooms can provide up to 5 µg of vitamin D, which is already half of your requirements. This equates to 4-5 chestnut mushrooms, 1-2 portobello mushrooms or 14 baby mushrooms. A great way to get some vitamin D in all year round.
The optimum amount of uv radiation needed, storage conditions and cooking methods as well as the physiological benefits of mushroom-derived vitamin D2 compared with solar-derived vitamin D3 also require further investigation.
Pictured below is a dried mushroom crisp which I had never tried before. My verdict - really delicious!