Patient's question:
What foods are low in phenylalanine? Why is the control fluctuating? How to make a recipe? How often should you review it?Doctor's answer:
Hello, the low-phenylalanine diet therapy is currently the only method for treating classic phenylketonuria (PKU). The goal of treatment is to prevent brain damage. The low-phenylalanine diet is primarily suitable for patients with typical phenylketonuria and those with persistently elevated phenylalanine levels above 1.22 mmol/L in the blood. Since phenylalanine is an essential amino acid for protein synthesis, complete deficiency can also lead to neurological damage. Therefore, infants can be fed specially formulated low-phenylalanine formula milk, and when introducing complementary foods during the toddler stage, starchy foods, vegetables, and fruits should be prioritized as low-protein options.The required phenylalanine intake is approximately:
- For infants under 2 months: 50–70 mg/(kg·d)
- For infants aged 3–6 months: 40 mg/(kg·d)
- For children aged 2 years: 25–30 mg/(kg·d)
- For children over 4 years: 10–30 mg/(kg·d)
It is ideal to maintain blood phenylalanine levels between 0.12–0.6 mmol/L (2–10 mg/dL).
Dietary control should be maintained at least until after puberty.
Recommendation: It is advisable to consume plenty of fresh vegetables and fruits, with low-phenylalanine starchy foods like sweet potatoes, yams, and starch as the primary diet. To ensure the physiological role of protein, sufficient calories must be provided, which can be supplemented with sugar or fats. When introducing complementary foods, blood tests should be conducted weekly to adjust the diet accordingly, ensuring both dietary diversity and stable blood phenylalanine levels.
Dietary therapy is a long-term process, and the cooperation of parents and the child is crucial for controlling blood phenylalanine levels. Wishing you a speedy recovery!