Nutritional benefits All types of edible mushrooms contain varying degrees of protein and fiber. They also contain B vitamins as well as a powerful antioxidant called selenium, which helps to support the immune system and prevent damage to cells and tissues. In particular, white button mushrooms are one of the few vitamin D. When they are grown, whether indoor or outdoor, they are exposed to UV light which increases their concentration of vitamin D. Mushrooms are being increasingly researched and used for their important health benefits with different varieties having different medicinal properties. Product of Australia. You can contact us for more information.