Results: General knowledge about the diet and the disease was very good. In contrast, only a small majority showed good compliance, especially only moderate results for 'RC', 'QP' was achieved. No significant correlations were found between the degree of knowledge, the four individual compliance-scores, the total compliance-score and follow-up analyses of metabolites. An individualized approach by co-consultations with dietitian/psychologist is organized for "problem-cases". Background: low protein diet, avoidance of fasting and emergency regimen is the primary treatment of MMA. CKD as a complication necessitates dietary adaptation. Objectives: review of dietary manipulations in children with decreasing glomerular filtration rates (GFR), routinely measured from age 2y. Case series: MMAVitamin B12 non-responsive n=14; age at presentation, neonatal (n=9) to 1.5y, current ages: 1mth to 16y (median 7.8y). MMA B12 responsive n=12; age at presentation, neonatal (n=2) to 4y, current ages: 2mths to 16y (median 6.3y). Results: Cross section of GFR from last 2y. Non B12 responsive: mild CKD, GFR 60-89 ml/min/1.73 m squared n=3; moderate or severe CKD, GFR <59 n=9, aged 2 to 12y. Four children with moderate CKD, aged 2 to 5y. Vomiting, reflux, repeated illness and poor fluid intake cause episodic dehydration. Fluid intake is increased above normal as CKD progresses/ during illness. If renal bone disease, phosphate restricted further and vitamin D analogues/phosphate binders given. Normal calcium intake unless hypercalcaemic. Potassium restriction rarely necessary. B12 responsive: mild CKD n=7, others normal. No further dietary manipulations. Conclusion: Early monitoring of kidney function is indicated. Episodes of dehydration contribute to deterioration in kidney function, regular dietary assessment of fluid, electrolytes and energy intake are therefore essential. Introduction: In PKU, it is established that optimal blood phenylalanine control is dependent on adequate dietary knowledge of caregivers/patients. In practice, dietitians spend substantial time on caregiver education, in order to improve their diet understanding and treatment adherence. Aim: an audit to assess caregiver's practical knowledge and understanding of a low phenylalanine diet. Methods/Subjects: 26 caregivers of 32 children (median age 7.4y: range 10 months-16y) were visited at home. They completed a multiple choice questionnaires and a series of practical tests to review their understanding of dietary management of PKU. Results: 40% were unable to calculate all 1 g protein (50 mg phenylalanine) exchanges from food labels; 30% failed to identify the amount of natural protein in one phenylalanine exchange; 50% were unable to correctly estimate by 'eye' the number of phenylalanine exchanges in common foods; 40% and 80% respectively, were unable to correctly define a low phenylalanine 'free' food or the protein content of 'free' vegetable sauces. 80% reported they weighed phenylalanine exchanges >50% of time.