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Vitamin D and mushrooms

Hi everyone

My husband heard a piece on the radio the other day about mushrooms and how they soak up the sun. As most are grown in grow bags these days, I did wonder how the vitamin d reached them, apparently if you leave your mushrooms in the sunshine for half an hour before you cook them they soak up vitamin D. Of course you do have to have sunshine. I use quite a lot in stir fry and have been diligently leaving them in the sun for half an hour before I cook them. Here’s hoping.

Wendy x

hi wendy,

my husband told me the same thing yesterday and i definitely think it’s worth a go…fingers crossed for a good summer! xxx

Nice tip!

Thanks :slight_smile:

Karen x

I heard yesterday about a friend’s daughter who has severe vitamin D deficiency. Her levels are down below 20 nmol/l. She had her levels tested because she has a hairline fracture in one of the bones in her foot which has been there for months and has not healed and because she has been very susceptible to infections and also (I think) lethargic for months. Anyway, the point of this story is that her parents were told it’s very difficult/impossible to get more than 20% of the vitamin D you need from food alone. It may be the case that this is only true if you start from an extremely low level - I’m not sure. I’d say we should all be supplementing.

My friend told me that too. :slight_smile:

Wikipedia contains an interesting explanation of why/how edible mushrooms do this (remarkable) thing, but note the important bit about the TYPE of vitamin D they produce:

Mushrooms that have been exposed to ultraviolet (UV) light contain large amounts of vitamin D2. Mushrooms, when exposed to UV light, convert ergosterol, a chemical found in large concentrations in many mushrooms, to vitamin D2. This is similar to the reaction in humans, where Vitamin D3 is synthesized after exposure to UV light.

Testing showed an hour of UV light exposure before harvesting made a serving of mushrooms contain twice the U.S. Food and Drug Administration’s daily recommendation of vitamin D, and 5 minutes of UV light exposure after harvesting made a serving of mushrooms contain four times the FDA’s daily recommendation of vitamin D. High performance liquid chromatography analysis has also demonstrated the effect sunlight has on mushroom vitamin D2 content.

The ergocalciferol, vitamin D2, in UV-irradiated mushrooms is not the same form of vitamin D as is produced by UV-irradiation of human skin or animal skin, fur, or feathers (cholecalciferol, vitamin D3). Although vitamin D2 clearly has vitamin D activity in humans and is widely used in food fortification and in nutritional supplements, vitamin D3 is often used in dairy products.

Mushroom Sunlight exposure Vitamin D2 content (IU/100g):

Shiitake (with no sunlight exposure: 10 — 100
Shiitake (with sunlight exposure, gills down): 11,000
Shiitake (with sunlight exposure, gills up): 46,000

Reishi (with no sunlight exposure): 66
Reishi (with sunlight exposure, pores up): 2,760

Maitake (with no sunlight exposure): 460
Maitake (with sunlight exposure, pores up): 31,900

Safe sun exposure still appears to be the best way to get your vitamin D, which of course is actually a hormone and not a true vitamin, but some sunny mushrooms sound healthy - and that’s how they make vitamin D pills anyway!

Lolli xx

Thank you for all your replies folks; certainly interesting and yes sunshine is the best way to get it D3, if you can stand it and I know many MSs find it difficult to sit in the sun. Somewhere like Fueventura in the Canary Islands in a good place as there’s a nice breeze out there at the moment, so I’m told.

One MS nurse once told me to eat fruit and veg that are brightly coloured and are ripened in the sunshine!

Wendy x

Vitamin D2 is much more dangerous if you have large amounts than D3