Evaluation of serum Vitamin B12 level and related nutritional status among apparently healthy obese female individuals

Objective: Obesity is a major public health problem and great risk for not only cardiovascular diseases but also cancer, musculoskeletal, and gynecological diseases. This study was aimed to investigate the association between serum Vitamin B12 (vitB12), body mass index (BMI), and nutritional status among obese women. Methods: This cross-sectional study enrolled consecutive female subjects. The consumptions of red meat, fish, bovine liver, egg, and mushroom were recorded. According to the Dietary Reference Intakes, the patients were categorized as insufficiency and sufficiency. Three cutoff points were defined for vitB12 status: (1) Deficiency if vitB12 is < 200 pg/mL; (2) insufficiency if vitB12 is 250-350 pg/mL, and (3) sufficient if vitB12 is >= 350 pg/mL. According to BMI, the patients were assigned to nonobese and obese groups. BMI, serum vitB12 level, consumptions of red meat, fish, bovine liver, egg, and mushroom were evaluated and compared between two groups. Results: Mean level of vitB12 was 247.8 +/- 10.4 pg/mL and significantly associated with consumption of egg (P = 0.031), bovine liver (P = 0.004), mushroom (P = 0.040), and red meat (P = 0.003). VitB12 was significantly higher in nonobese than obese group (282.5 +/- 106.8 vs. 242.5 +/- 107.5 pg/mL, P = 0.001). The ratio of vitB12 deficiency was significantly higher in obese than nonobese group (37.6% vs. 24.7%; P = 0.019). VitB12 level was negatively correlated with BMI (r = -0.155; P < 0.001), but not insulin resistance (r = -0.172; P = 0.062). Conclusion: Obesity was associated with low level of vitB12 in obese women, and more likely to be vitB12 deficient. Consumption of certain types of food contributes to increase vitB12 level.