A new, low-volume protein substitute for teenagers and adults with phenylketonuria

Some older patients with phenylketonuria (PKU) fail to consume their protein substitute (with or without vitamin and mineral supplements) in prescribed amounts, which contributes to poor blood phenylalanine control. PKU Express (Vitaflo), is a new low-volume (amino acids 72 g/100 g), low-carbohydrate, phenylalanine-free protein substitute with added vitamins and minerals designed for people with PKU over 8 years of age. In an open intervention study, the aim was to investigate its acceptability and effectiveness in a group of teenagers and adults with PKU. Twenty-three subjects (15 female; 8 male) with PKU, who had a median age of 17 years (range 8-37 years) took the substitute for 8 weeks. A 3-day prospective diet diary, height, weight, plasma amino acids, biochemical and haematological nutritional analytes were measured at weeks 0 and 8. Skin-puncture bloods for plasma phenylalanine were collected every 2 weeks. The median weight of protein substitute (with or without vitamin and mineral supplements) consumed decreased by 33% from 150 g (range 140-180) daily to 100 g (range 100-125) daily ( p