ProZeroProZero is a low protein milk replacement consisting of carbohydrate and fat for use in the dietary management of inborn errors of metabolism from 6 months of age. It can used be in a similar way to milk, e.g. as a drink, on cereal, in tea or coffee and in recipes.ProZero is a food for special medical purposes and should only be used under medical supervision.ProZero contains milk fats and milk sugar (lactose).