A nutritional supplement powder and method of supplementing the nutritional value of a food or beverage is provided. The nutritional supplement powder includes a protein system, vitamins, minerals, and fiber. The protein system has a water solubility of at least about 70% at room temperature. The nutritional supplement powder is essentially free of divalent ions of copper, iron, and zinc, and is also essentially free of vitamin C. When added to a food or beverage, the nutritional supplement powder does not substantially change the organoleptic properties of the food or beverage.