Fig. 6From: Status of nutrients important in brain function in phenylketonuria: a systematic review and meta-analysisVitamin B12 levels in PKU patients versus healthy controls. Results of meta-analyses for Vitamin B12 levels in PKU patients versus healthy controls. Abbreviations: LCL, lower confidence limit; REML, restricted maximum likelihood; SD, standard deviation; SMD, standardized mean difference; UCL, upper confidence limitBack to article page