The study "Vitamin B12 Levels of Subjects Aged 0–24 Year(s) in Konya, Turkey" establishes reference ranges for Turkish youth, highlighting that vitamin B12 levels decrease with age, with a higher prevalence of deficiency among adolescent boys. Based on 1,109 samples, researchers defined normal levels for boys at 127–576 pg/mL, crucial for addressing deficiencies that impact neurological development. Read the full study at PMC .