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Journal of Nutrition and Metabolism
Volume 2017, Article ID 6859820, 17 pages
Clinical Study

Metabolomic Insights into the Nutritional Status of Adults and Adolescents with Phenylketonuria Consuming a Low-Phenylalanine Diet in Combination with Amino Acid and Glycomacropeptide Medical Foods

1Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
2Boston Children’s Hospital, Harvard Medical School, Boston, MA, USA
3Department of Molecular and Medical Genetics, School of Medicine, Oregon Health and Science University, Portland, OR, USA

Correspondence should be addressed to Denise M. Ney; ude.csiw.icsirtun@yen

Received 7 July 2017; Accepted 23 October 2017; Published 31 December 2017

Academic Editor: Ellen Crushell

Copyright © 2017 Bridget M. Stroup et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Background. Nutrient status in phenylketonuria (PKU) requires surveillance due to the restrictive low-Phe diet in combination with amino acid medical foods (AA-MF) or glycomacropeptide medical foods (GMP-MF). Micronutrient profiles of medical foods are diverse, and optimal micronutrient supplementation in PKU has not been established. Methods. In a crossover design, 30 participants with PKU were randomized to consume AA-MF and Glytactin™ GMP-MF in combination with a low-Phe diet for 3 weeks each. Fasting venipunctures, medical food logs, and 3-day food records were obtained. Metabolomic analyses were completed in plasma and urine by Metabolon, Inc. Results. The low-Phe diets in combination with AA-MF and GMP-MF were generally adequate based on Dietary Reference Intakes, clinical measures, and metabolomics. Without micronutrient supplementation of medical foods, >70% of participants would have inadequate intakes for 11 micronutrients. Despite micronutrient supplementation of medical foods, inadequate intakes of potassium in 93% of participants and choline in >40% and excessive intakes of sodium in >63% of participants and folic acid in >27% were observed. Sugar intake was excessive and provided 27% of energy. Conclusions. Nutrient status was similar with AA-MF and Glytactin GMP-MF. More research related to micronutrient supplementation of medical foods for the management of PKU is needed.