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Weird Science

Updated: Oct 23, 2023

Mushrooms + Sunlight = Vitamin D

assorted mushrooms
Mushrooms + Sunlight = Vitamin D

Few foods in the Western diet are a good source of vitamin D, with the best naturally occurring dietary source being oily fish.

Some countries have liberal fortification policies, with foods such as milk, margarine, breakfast cereals, and juices, fortified with vitamin D. Sun-dried and UV radiation-exposed mushrooms are a potentially important source of dietary vitamin D (as vitamin D2) and are the only non-animal food product with substantial amounts of bio-available vitamin D and, as such, have the potential to be a primary source of dietary vitamin D for vegans, vegetarians and a great option for anyone else.

  • Vitamin D stimulates the synthesis of calcium, enhancing the absorption of dietary calcium and thereby reducing the risk of osteomalacia in adults and rickets in children.

  • Adequate vitamin D is also important for muscle function and reducing the risk of falls in the elderly and may help protect against some cancers, respiratory disease in children, cardiovascular disease, neurodegenerative diseases, and both type 1 and type 2 diabetes.

  • Vitamin D also has implications with regards to semen quality, PCOS and female fertility.

  • Although classified as a vitamin,vitamin D can be produced by the body in sufficient quantities when the skin is exposed to ultraviolet (UV) radiation from the sun.

  • If sunlight exposure is limited, dietary sources of vitamin D are required to maintain healthy circulating concentrations.

The How of it...

green tree forest

Exposing mushrooms to UV for 15 minutes (from sunlight or in a laboratory) increases the amount of vitamin D in mushrooms by nearly eight fold.

Putting five store-bought button mushrooms in the sun, or just one portobello mushroom, produces 24 µg of vitamin D, which translates to nearly 1000 international units, providing the amount of vitamin D one needs in an entire day, and the equivalent found in most vitamin D supplements.

We are what we eat....

So keep your share of that $100 million we Australian's spend annually on vitamin D supplements in your pocket and experiment with what we all need to do quality food because in essence, we are what we eat.

"Healthy people should get vitamin D from small doses of sunshine every day as well as from food, such as fish, oil, mushrooms and dairy products”.

Tim Spector, Professor of Genetic Epidemiology, King's College London. Read here.

So what are the best and how do I use them?

References and further reading:


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