Abstract

The aim of this narrative review is to investigate dietary management in patients with phenylketonuria (PKU) treated with pegvaliase, focusing on clinical and psychological impacts, nutritional challenges, and best practices. Due to the recent introduction of pegvaliase, patient attitudes and dietary management, as well as the clinical and psychological effects of nutritional changes, remain underexplored.

A PubMed search using terms such as “pegvaliase,” “phenylketonuria,” and “diet/nutrition changes” included studies on humans published in English over the past 20 years. Relevant data on dietary adjustments, psychological outcomes, and adherence were analyzed.

Effective pegvaliase management requires dietary adjustments consistent with dose adjustments, aiming to achieve adequate phenylalanine (Phe) levels. Micronutrients (e.g., zinc, selenium, vitamins D and B12) and nutritional status are mandatory variables to be taken into consideration, focusing on the patient’s overall health. Pegvaliase enables increased natural protein intake, reduced reliance on medical protein substitutes, and dietary liberalization, enhancing nutritional adequacy and quality of life. However, psychological challenges, including anxiety and food-related neophobia, can complicate the management of the diet and, therefore, therapy.

Multidisciplinary care, combined with education for patients and caregivers, is vital to achieving sustainable clinical and psychological outcomes in pegvaliase-treated PKU patients. Long-term studies are needed to refine guidelines and establish high standards of care.