How is PKU monitored?

PKU is monitored with three main tools:

  • monthly blood phe levels
  • regular visits to the PKU Clinic
  • monthly food records

Monthly blood tests help people with PKU track their progress with the diet. These blood tests measure phe build-up in the blood. (High levels indicate too much phe from food or too little Phenyl-Free*.) People with PKU should keep their blood phe levels in the safe range, between 1 and 6 mg/dL.

Regular measurement of blood phe levels can be done in 2 ways:

  • a blood draw in a hospital or clinic, which directly measures phe in the blood
  • a collection of a blood sample on a filter paper at home, which is mailed to the laboratory for analysis

Regular visits to the PKU clinic are an important opportunity for people with PKU to meet with the PKU team. During these visits, everyone on the team works together to give the best possible care and guidance for people with PKU. The visit should include a blood draw, a short exam by a pediatrician, and a chance to discuss ways to manage the low-phe food pattern. The nutrition education activity for children and parent support group for families are important components of the clinic visit at the University of Washington.

Food records are usually a 3 day diary of all foods and beverages eaten and the amounts consumed. These diaries should be accurate records of foods eaten. They will help the PKU clinic team to interpret blood phe levels and make adjustments to the food and formula prescription.

* Phenyl-Free is a registered trademark of Mead Johnson Co. A number of other formulas are available.

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