Because individuals with PKU are unable to convert excess PHE to TYR, daily intact protein intake must be limited to only the amount that provides the PHE required for anabolism. PHE-restricted medical foods provide amino acids to meet the remaining protein and energy recommendations, and supplemental TYR. Most medical food products provide vitamins, minerals, carbohydrates and fats that would ordinarily be consumed in foods that are restricted for individuals with PKU. When free amino acids provide the bulk of protein equivalents, the recommendation for protein intake is increased. The Daily Recommended Intake (DRI) for nutrients other than total protein, PHE and TYR are not increased over that recommended for the healthy, general population. Either poor adherence to dietary and medical food recommendations, or reliance on an incomplete medical food can place the individual with PKU at risk for nutrient deficiencies. There is not sufficient evidence at this time to alter recommendations for energy or vitamin D and calcium for individuals with PKU.