The combined self- and parent-rated SDQ score profile predicts care use and psychiatric diagnoses

European Child & Adolescent Psychiatry - The Strengths and Difficulties Questionnaire (SDQ) is widely used, based on evidence of its value for screening. This evidence primarily regards the...     

Serum vitamin B12 concentrations within reference values do not exclude functional vitamin B12 deficiency in PKU patients of various ages

Homocysteine (Hcy) and in particular methylmalonic acid (MMA) are considered reliable parameters for vitamin B₁₂ status in healthy individuals. Phenylketonuria (PKU) patients are at risk for functional vitamin B₁₂ deficiency based on their diet.ObjectiveThe aim of this study was to investigate the prevalence of functional vitamin B₁₂ deficiency in continuously treated PKU patients and the association of parameters of vitamin B₁₂ and metabolic control.MethodsIn 75 continuously treated PKU patients of 1–37 years of age, serum vitamin B₁₂ concentrations, plasma Hcy, MMA, and phenylalanine concentrations were studied.ResultsEight patients had vitamin B₁₂ concentrations below normal. Out of these eight patients, two had elevated MMA and/or Hcy concentrations. Ten other patients with normal vitamin B₁₂ concentrations had elevated concentrations of MMA and/or Hcy.ConclusionsA vitamin B₁₂ concentration within the reference range does not automatically imply a sufficient vitamin B₁₂ status. We recommend measuring serum MMA, or alternatively plasma Hcy, yearly in all PKU patients to diagnose functional vitamin B₁₂ deficiency.