Mushrooms cut into slices are called as sliced mushrooms.Low in calories and fat and cholesterol-free, mushrooms contain a modest amount of fiber and over a dozen minerals and vitamins, including copper, potassium, magnesium, zinc and a number of B vitamins such as folate. Mushrooms are also high in antioxidants like selenium and glutathione, or GSH, substances believed to protect cells from damage and reduce chronic disease and inflammation.