Silk Original All Natural Soymilk*. Lactose & dairy-free. 6g heart healthy soy protein. 90 calories per cup. *With added vitamins. As part of a diet low in saturated fat and cholesterol, 25 grams of soy protein per day may reduce the risk of heart disease. A serving of Silk original provides 6.25 grams of soy protein. One quart (946 ml).