Comparison of vitamin B12 levels in normal WEİGHT and obese patients in obesity and family medicine outpatient clinics

Objective: Vitamin B12, which is essential for the human body and plays a role in many cellular functions, affects many systems, especially hematological and neurological systems, and is affected by many genetic, environmental and nutritional conditions. In this study, we aimed to compare vitamin B12 levels between normal weight and obese individuals. Method: In our descriptive cross-sectional study, the data of 564 patients aged between 18-65 years who applied to the family medicine and obesity polyclinics of our university hospital between September 2017 and December 2018 were analyzed retrospectively. Patients were divided into 2 groups according to body mass index: Group 1: Normal weight (BMI: 18.5-24.9 kg/m²), Group 2: Obese (BMI: ≥ 30 kg/m²). The reference range for serum vitamin B12 is 126-505 pg/ml. Vitamin B12 levels were compared between Group 1 and Group 2. In addition, the relationship between patients' sociodemographic characteristics, smoking and alcohol use, comorbid chronic diseases, and BMI and vitamin B12 levels were examined. Results: 26.4% of the patients were male and 73.6% were female. The mean age was 35.6±12 years. Of the patients, 38.5% were of normal weight and 61.5% were obese. The mean vitamin B12 level of Group 1 was 252.4±115.1 pg/ml, while that of Group 2 was 211.1±90.1 pg/ml. There was a significant difference between the groups in terms of serum vitamin B12 levels (p<0.001). Vitamin B12 level measured in normal weights was significantly higher than in obese ones. While the rate of those with vitamin B12 levels <126 pg/ml was significantly higher in obese compared to those with normal weight, the rate of those with vitamin B12 levels between 126-505 pg/ml was significantly lower (p<0.05). There was a significant negative correlation between BMI and vitamin B12 (r=-0.170 p<0.001). Conclusion: A significant relationship was found between obesity, which is a common health problem today, and vitamin B12 levels. Obese subjects had lower vitamin B12 levels and higher rates of vitamin B12 deficiency.