Treatment for PKU : Diet restrictions

Treatment

The main concept in Phenylketonuria(PKU) treatment is to reduce the level of phenylalanine(phe)  in blood for normal brain development. An individual’s blood phe level depends on dietary intake of phenylalanine and the residual activity of phenyalanine hydroxylase(PHA).

Dietary management

The goals of this management is to prevent excessive accumulation of phe by controlling the intake of natural proteins at the same time allowing for normal growth and micronutrient biochemical status. usually through phe-free protein substitutes to account for the reduced protein intake.
Patients with PKU should adhere to a semi-synthetic diet is used which comprises of:

• Foods with low phe content such as many fruits and vegetables
• Weighed amounts of foods containing medium amounts of phe (e.g. broccoli, potato).
• Protein substitutes e.g. Phe-free amino acid mixtures to provide normal or supra-normal total protein intake
• vitamins, minerals and trace elements.

 The amount of phe ingested is often calculated using an exchange system. In the UK system 1 ‘exchange’ = 50 mg phe which is approximately 1 g protein

The precise tolerance for phe varies, but for most individuals with PKU it is between 200 and 500mg/day. furthermore, the phe tolerance of the individual may change over time, so careful and continuous monitoring of the individuals whose phe intake is restricted is necessary to avoid both elevations and deficiencies of phe.

References:

• ScienceDirect.com - Paediatrics and Child Health - Phenylketonuria. 2013. ScienceDirect.com - Paediatrics and Child Health - Phenylketonuria. [ONLINE] Available at: http://www.sciencedirect.com/science/article/pii/S1751722210001836. [Accessed 17 January 2013].