Australian researchers have found that exposing mushrooms to UV light can make them a major source of vitamin D.
Mushrooms contain a high level of the ingredient ergosterol, needed for vitamin D.
But as the crop is usually grown in the dark, no conversion to vitamin D can take place.
However, research done by the University of Western Sydney has found that when mushrooms are exposed to UV light, they produce and then retain vitamin D for eight days afterwards.
Dr. Gerald Pang and colleagues from the university tested the impact of irradiating Agaricus bisporus mushrooms with UV-C light from a xenon lamp from between 2 seconds to 30 minutes.
They found that placing the lamp the right distance away and exposing the mushrooms for the right length of time gave no impact on their colour while boosting their vitamin D concentrations.
Greg Seymour, president of the The International Society for Mushroom Science and general manager of the Australian Mushroom Growers' Association, said evidence suggests that 100 grams of irradiated mushrooms could provide the recommended daily intake of vitamin D.
However, nutritionist, Dr. Rosemary Stanton, has warned about the impact of the ultraviolet light on mushrooms.
She said that mushrooms are rich in some B group vitamins, which are very sensitive to heat and light.
"You would have to be really careful that it doesn't destroy the B-group vitamins in mushrooms," ABC Online quoted Stanton as saying.
The findings are published in the Journal of Agricultural and Food Chemistry.