It is known that vitamin B12 and certain trace elements possess antioxidant properties; however, the mechanisms underlying these relationships have not been fully elucidated. The aim of this study was to evaluate the relationship between serum levels of vitamin B12, selenium (Se), cobalt (Co), copper (Cu), zinc (Zn), iron (Fe), and manganese (Mn) in patients with vitamin B12 deficiency compared to healthy controls. The study included a total of 50 patients with vitamin B12 deficiency and 40 healthy controls. Serum levels of Se, Co, Cu, Zn, Fe, and Mn were measured using inductively coupled plasma optical emission spectrometry (ICP-OES), while biochemical parameters were assessed using an automated analyzer. Statistical analysis was conducted with SPSS 21.0 statistical software (SPSS, Chicago, IL, USA), with a P-value of <0.05 considered statistically significant. Serum levels of vitamin B12, Zn, Mn, Co, Fe, and iron binding capacity were significantly lower in the vitamin B12 deficiency group compared to controls. Positive correlations were observed between vitamin B12 and Se, Fe and mean corpuscular volume (MCV), Fe and ferritin, Zn and Cu, and Zn and Se. Conversely, negative correlations were found between vitamin B12 and Fe, Se, and Mn in the vitamin B12 deficiency group. Our data suggest that the interactions among circulating Zn, Mn, Co, Fe, and vitamin B12 are significant in the oxidant/antioxidant balance and may play a crucial role in the antioxidant properties observed in patients with vitamin B12 deficiency.