You may have previously wondered, do mushrooms have Vitamin D?
Particularly useful to take when there’s no sunlight in winter.
Like if you slice them open and expose them to sunlight, can it boost Vitamin D levels?
But you’re not exactly sure how mushrooms generate Vitamin D, what should you consume and how much?
Should you swap those Vitamin D capsules for mushrooms?
In this article, you’re going to learn how mushrooms make Vitamin D and are they effective for the human body?
Can you leave mushrooms under a UV lamp to boost Vitamin D levels?
So stick around and carry on reading.
Vitamin D — An Overview
Perhaps you already know, but some background on Vitamin D is necessary before we dive any deeper.
Vitamin D is one of the most important nutritional vitamins of the human body.
It regulates the absorption of calcium and phosphorus from your diet and lifestyle.
Calcium and phosphorus are critical elements, required for healthy bones and teeth.
Besides this, Vitamin D also
- Strengthens muscles
- Boosts immunity
- Helps ease depression
- Increases chances of weight loss
Vitamin D is a compound composed of several types. But the two most important ones are
Vitamin D2 (Ergocalciferol)
This type of Vitamin D comes from plant sources like mushrooms, fungi and yeast.
It’s different from the type of Vitamin D that’s generated by your skin when exposed to sunlight. Do Mushrooms Have Vitamin D
Vitamin D3 (Cholecalciferol)
This is the type of Vitamin D that your skin generates when exposed to UVB rays from the sun.
It’s the body’s most natural form of Vitamin D, synthesized and consumed with ease.
Besides the sun and your skin, Vitamin D3 comes from animal sources of food like oily fish, eggs, liver and red meat.
Knowing the difference between Vitamin D2 and D3 is key to meeting your body’s Vitamin D needs.
Mushrooms — An Overview
Mushrooms are one of the most widely consumed food in the world.
There are around 14,000 species of mushrooms in the world, out of which around 300 are edible by humans.
As of 2017, about 34 million tonnes of mushroom are produced worldwide and China is the world’s largest producer (approx 75%).
The Button Mushroom is the world’s most consumed variety making up 40–50% of the global production.
Mushrooms have become popular as a plant-based option to meat and essential food of a vegan lifestyle.
Do Mushrooms Have Vitamin D? (The Fungi Science)
In the previous section, I spoke about Vitamin D2 and how it comes from mushrooms and fungi.
This answers the question – do mushrooms have Vitamin D? Yes, they do. But only Vitamin D2.
Let’s take a look at exactly how this happens from a scientific side.
Mushrooms have a chemical compound called Ergosterol in their cell walls.
Like how humans and animals have a compound called cholesterol in our skin which produces Vitamin D3 when exposed to sunlight.
When mushrooms are exposed to UV rays from the sun, the Ergosterol from their cell walls undergoes photochemical reactions to produce Vitamin D2 precursors.
These Vitamin D2 precursors are then thermally isomerised in a temperature-dependent process to produce Ergocalciferol.
Michael F. Holick, (PhD, M.D., director of the Vitamin D, Skin, and Bone Research Laboratory at Boston University School of Medicine and author of The Vitamin D Solution) says
“Similar to when humans are exposed to sunlight (or a sunlamp), mushrooms convert a precursor to vitamin D, called ergosterol, into vitamin D₂ when exposed to UV light. “It turns out that just about anything with the precursor to Vitamin D when exposed to sunlight, will develop vitamin D.”
This is the Vitamin D2 that’s available for use.
Can I Expose Mushrooms To Artificial UV Light?
So, you now know that mushrooms can generate Vitamin D2 when exposed to sunlight.
But what if there’s no sunlight? Would it still work?
I explained the 3 types of Ultraviolet (UV) wavelengths in our article about how is vitamin d made by your skin.
In summary, there are 3 types of UV wavelengths from the sun
- UV-A rays (Longest)
- UV-B rays (Medium)
- UV-C rays (Shortest)
UV-C rays are the most dangerous but luckily the Earth’s Ozone Layer filters these out.
When exposed to UV-B rays, our skin generates Vitamin D3.
Studies were done to test the amount of Vitamin D produced by mushrooms when exposed to artificial UV radiation.
These studies used Fluorescent UV lamps and Pulsed UV lamps.
Although the amount of Vitamin D produced in fresh or dried mushrooms didn’t significantly vary, the Pulsed UV lamps produced high levels of Vitamin D much faster than standard Fluorescent UV lamps.
With low exposure time (often 1–3 seconds), it achieved at least 10 μg D2/100 g of fresh mushroom fixed weight.
Due to the shorter exposure time, there was also less discolouration on the surface which let’s be honest, is more appealing to us consumers.
So UV lamps can be used but these are often done at the commercial level than at home.
Vitamin D Content Of Wild, Fresh And Dried Mushrooms
You now know that mushrooms are a good source of Vitamin D2.
Although, this is different to what the human body produces (Vitamin D3) and is not a replacement for Vitamin D3.
Let’s look at the Vitamin D content generated by various types of mushroom, so you can decide which to consume.
Is Mushroom High In Vitamin D?
Yes, mushrooms contain a high amount of Vitamin D, but only when exposed to UV-B light.
According to research, without UV-B light, fresh retail mushrooms only contain about 1 μg/100 g.
When exposed to UV-B light, mushrooms generate as much as 10 μg Vitamin D2/100 g.
Wild mushrooms contain more Vitamin D2 than retail mushrooms.
Wild mushrooms are found in the wild and not grown especially for human consumption.
As they spend a large amount of time in the sun, fresh wild mushrooms contain more Vitamin D2 than retail mushrooms.
Depending on the species the amount of Vitamin D2 may change.
Some varieties like Maitake, Chanterelles and Morels may contain up to 3–30 μg Vitamin D2/100 g of fresh weight.
Fresh Retail Mushrooms
The Shiitake Mushroom is a species native to East Asia and makes up about 17–20% of global mushroom consumption.
Fresh retail Shiitake or Button mushrooms contain less than 1 μg/100 g full weight of vitamin D2.
According to an article published in the Huffington Post, Vitamin D2 levels in Shiitake mushrooms soared up to 1,000 μg per 100 grams after 12 hours of sun exposure.
Although you don’t need to keep them that long in the sun, a 20-minute exposure will generate 10 times more Vitamin D2.
Dried mushrooms are a great alternative to fresh mushrooms.
They’re only about 20% of the weight of fresh mushrooms and easier to transport and store.
Yes, 80% of the mushroom weight is water, that’s why they shrink so tiny when cooked.
Some used practices in drying mushrooms include
- Sun drying
- Hot air drying
- Freeze drying
An analysis of the Vitamin D2 content in sun-dried mushrooms in China revealed they contained between 7–25 μg of Vitamin D2/g of Dried Mass.
The Chanterelles type of mushroom collected from Swedish forests had a Vitamin D2 content of 0.12 – 6.30 μg / g of dried mass.
This was after collection, hot air-dried and stored in darkness for 2–6 years.
The amount of Vitamin D2 varied from 15 μg/g dried mass to 25 μg/g dried mass.
Freeze-dried oyster mushrooms generated close to 35 μg D2/g dried mass, shiitake over 60 μg D2/g dried mass, and button mushrooms up to 119 μg D2/g dried mass after 30 min of exposure.
Although exposing dried mushrooms to UV light boosts Vitamin D2 levels, it is not standard commercial practice.
The drying temperature, moisture, humidity, storage and UV exposure time influence the amount of Vitamin D2.
Bioavailability of Vitamin D from Mushrooms
A study was done over a 3 month period on 30 adults to assess the bioavailability of Vitamin D2.
These adults were split into groups and given 2000 IU (50 μg) of supplemental Vitamin D2, Mushroom Vitamin D2 and Vitamin D3.
Mushroom Vitamin D2 was as effective as Vitamin D2 supplements in raising Vitamin D2 in the blood.
Although Vitamin D2 from mushrooms is less effective than Vitamin D3, it’s still popular among vegetarians and vegans.
Does Cooking Mushrooms Destroy Vitamin D?
No, cooking mushrooms does not destroy Vitamin D but may reduce it.
Few studies have shown that the duration and cooking method influenced the amount of Vitamin D retained in mushrooms.
When pan-fried without oil, about 85–88% of the Vitamin D2 was retained while boiling or baking retained 65–67% of the Vitamin D2.
How To Store Mushrooms?
So you’re now well aware of why mushrooms are a great source of Vitamin D2.
How do you store them so they keep their Vitamin D2 levels?
Studies suggest that UV radiated fresh mushrooms will keep their Vitamin D2 levels when refrigerated (about 2–4°C) for around 8 days.
In the case of hot air-dried mushrooms, they had good Vitamin D2 retention for up to 8 months when stored in dry, dark conditions (around 20°C).
But, there was a steady decline in Vitamin D2 levels beyond the 8 month period.
Store fresh radiated mushrooms for up to a week in the fridge and consume dried mushrooms within at least 8 months.
How To Expose Mushrooms To Sun At Home?
Maybe now you’re a big fan of mushrooms.
How could you not be? After all, they are tasty, full of nutrients and incredibly healthy.
Let’s say you want to prepare your own stack of mushrooms and expose them to the sun. How do you go about doing this?
So it’s best to do this during summer but if there’s sun during the winter where you live, feel free to give it a try.
Step 1 — Buy fresh button, shiitake or oyster mushrooms from your local supermarket.
Step 2 — Slice them up and place them evenly on a tray.
Step 3 — Dry them in the sun during the day (11–3 pm). Cover them at night to avoid the moisture from dew settling on them.
Step 4 — After drying them for a couple of days, store them in a sealed container.
Step 5 — Rehydrate them with a little bit of water when you wish to consume them.
The dried mushrooms should be good and last you for at least 1 year.
Vitamin D From Mushrooms vs Supplements
So mushrooms are one of the best sources of Vitamin D2.
After all, can you alter the nutrition properties of many foods? Probably not.
Mushrooms are also inexpensive, tasty and easy to store.
So should you swap your Vitamin D supplements and eat a bunch of mushrooms?
The answer is no.
As we explained above, your body needs Vitamin D3 to actively regulate and process the calcium and phosphorus in your body.
Vitamin D2 is good but it’s not a substitute for Vitamin D3.
If you live in a country with lots of sunshine then you probably don’t need Vitamin D supplements.
Still do check your Vitamin D levels to make sure.
If you don’t get enough sunshine, take Vitamin D3 supplements.
Or eat Vitamin D rich foods like oily fish, red meat, egg yolk, fortified cereal, milk to meet your daily intake.
If you live a vegan lifestyle, you may be wondering – is Vitamin D3 from Lanolin safe and what options do you have? We also introduce a vegan alternative to Lanolin – Lichen.
Now that you know about Vitamin D2 and D3, check for them in fortified milk, cereal or juices.
I hope this article helped answer the all-important question, do mushrooms have Vitamin D?
We compared the Vitamin D2 content of wild, fresh and dried mushrooms and how you should store them.
We also shared some steps on how you can dry your own mushrooms at home to maximise their Vitamin D2 content.
Do not replace your Vitamin D3 supplements or stop eating Vitamin D3 rich foods in favour of mushrooms.
Your body needs Vitamin D3 more than Vitamin D2.
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Here you’ll connect with fellow health lovers and learn all things Vitamin D, all things natural supplements.
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