Management
Guidelines
Portal
PKU Nutrition Management Guidelines
First Edition
March 2015, v.1.12
Updated: August 2016
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Nutrition Recommendations
Question
1. For individuals with PKU what nutrient intakes are associated with positive outcomes?
Conclusion Statement
Derived from evidence and consensus based clinical practice

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.

Recommendation 1.1

Meet the individual’s recommended PHE intake (for anabolism and maintaining an appropriate blood PHE concentration) by adjusting intact protein intake. See TABLE #3, Recommended Intakes of PHE, TYR and Protein for PKU for recommended intake ranges by age.

Strength of Recommendation:
Insufficient EvidenceConsensusWeakFairStrong
Clinical Action:
ConditionalImperative
Recommendation 1.2

Provide a total protein intake (from a combination of intact protein and amino acid-based medical food) approximately 50% higher than the DRI for infants and children from birth to 4 years of age ( TABLE #5, Comparison of Recommendations for Dietary Protein Intake for Infants and Children under 4 Years of Age to the 2015 GMDI/SERC Guideline Recommendation) and 20-40% higher than the DRI for those over 4 years of age ( TABLE #3, Recommended Intakes of PHE, TYR and Protein for PKU). The amount of medical food prescribed is based on the difference between the total protein recommendation and the intact protein allowance.

Strength of Recommendation:
Insufficient EvidenceConsensusWeakFairStrong
Clinical Action:
ConditionalImperative
Recommendation 1.3

Provide supplemental TYR if blood TYR concentrations are consistently below the normal range.

Strength of Recommendation:
Insufficient EvidenceConsensusWeakFairStrong
Clinical Action:
ConditionalImperative
Recommendation 1.4

With the exception of recommended intake for protein, PHE and TYR, individuals with PKU should meet the same DRI for age- and gender-specific nutrient/micronutrients and energy as healthy individuals in the general population

Strength of Recommendation:
Insufficient EvidenceConsensusWeakFairStrong
Clinical Action:
ConditionalImperative
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