Retrospective Study of Serum Vitamin D Levels and Metabolic-Associated Fatty Liver Disease in 222 Children and Adolescents Aged 6-18 Years With Obesity.

BACKGROUND Vitamin D deficiency is common in pediatric obesity and has been proposed to contribute to metabolic-associated fatty liver disease (MAFLD). This retrospective study aimed to evaluate serum 25-hydroxyvitamin D (25[OH]D) levels and MAFLD in 222 children and adolescents aged 6-18 years with obesity. MATERIAL AND METHODS Records of 222 patients with obesity (body mass index ≥95th percentile) were reviewed. Hepatic steatosis was assessed by abdominal ultrasonography; MAFLD was defined as hepatic steatosis in the presence of obesity. Anthropometric measures and routine metabolic laboratory results were extracted. Serum 25(OH)D was analyzed when available and categorized as deficient (<12 ng/mL), insufficient (12-20 ng/mL), or sufficient (>20 ng/mL). Groups with and without MAFLD were compared, and 25(OH)D was evaluated across steatosis grades. RESULTS MAFLD was identified in 135 of 222 patients (60.8%). Male sex was associated with higher likelihood of MAFLD (OR, 2.75; 95% CI, 1.46-5.16). The MAFLD group exhibited a less favorable metabolic profile, including higher HOMA-IR, HbA1c, ALT, and AST, and lower HDL-C (all P≤0.05) than non-MAFLD obesity group. Serum 25(OH)D was available in 148 participants and showed no difference between the MAFLD and non-MAFLD obesity groups (P=0.782); similarly, 25(OH)D levels were not associated with ultrasonographic steatosis grade (P=0.686). CONCLUSIONS MAFLD was common in pediatric patients with obesity and was associated with an adverse metabolic profile; however, serum 25(OH)D was not associated with MAFLD or steatosis grade. Clinical care should prioritize metabolic risk assessment, and prospective studies are required to clarify vitamin D's role in pediatric MAFLD.