Evaluation of serum vitamin B12 and folic acid levels in patients aged 8–14 years diagnosed with obesity

Objective: This study aimed to evaluate serum vitamin B12 and folate levels in children aged 8–14 years diagnosed with obesity and to compare these levels with those of healthy peers. Materials and Methods: A total of 200 children aged 8–14 years who were followed at the Department of Pediatrics, Akdeniz University Faculty of Medicine, were included in the study. The study population consisted of an obese group (n=100) and an age- and sex-matched healthy control group (n=100). Anthropometric measurements were obtained for all participants, and body mass index (BMI) and BMI Z-scores were calculated. Serum vitamin B12 and folate levels were assessed using laboratory analyses. Data were analyzed according to age groups (8–10 years and 11–14 years) and sex. Appropriate parametric and nonparametric statistical tests were applied, and a p-value <0.05 was considered statistically significant. Results: Median serum vitamin B12 (306.5 ng/L) and folate (7.7 μg/L) levels were significantly lower in the obese group compared with the healthy controls (485.5 ng/L and 8.6 μg/L, respectively; p<0.001 and p=0.015). The prevalence of vitamin B12 (12.0%) and folate (17.0%) deficiency was also significantly higher in obese children than in controls (p<0.001). BMI Z-score showed a moderate negative correlation with vitamin B12 levels (r=−0.441, p<0.001) and a weak negative correlation with folate levels (r=−0.193, p=0.006). When analyzed by age groups, serum vitamin B12 levels were significantly lower in obese children compared with controls in both the 8–10 and 11–14 age groups (p=0.001 and p<0.001, respectively). In contrast, folate levels did not differ significantly between groups in the 8–10 age group (p=0.170) but were markedly lower in obese children aged 11–14 years (p<0.001). The obese group, children aged 11–14 years had significantly lower vitamin B12 and folate levels than those aged 8–10 years (p=0.001 and p<0.001, respectively). The highest prevalence of vitamin deficiency was observed in obese children aged 11–14 years (vitamin B12: 16.1%; folate: 25.8%). Additionally, increasing age was significantly associated with decreasing vitamin B12 (r=−0.341) and folate levels (r=−0.417) in the obese group. No significant differences were found between girls and boys in terms of vitamin B12 or folate levels among obese children (p=0.096 and p=0.387, respectively). Conclusions: These findings indicate that childhood obesity is associated not only with increased body weight but also with adverse effects on vitamin B12 and folate status. Closer monitoring of these vitamins, particularly in obese adolescents, and the implementation of targeted nutritional interventions may be clinically important. Keywords: Adolescent; Body mass index; Child; Folate; Obesity; Vitamin B12