Subclinical vitamin $B_{12}$ deficiency is common in the elderly worldwide. We investigated the change of serum vitamin $B_{12}$ concentration with aging and compared anthropometric data and clinical health indicators between normal (${geq}$ 340 pg/mL) and low (< 340 pg/mL) serum vitamin $B_{12}$ groups in 470 Korean women aged 65 years and over living in a rural area. Serum vitamin $B_{12}$ concentration showed inverse correlation with age (r = -0.0992, p < 0.05). The normal $B_{12}$ group showed significantly (p < 0.05) higher red blood cell count, hemoglobin, and hematocrit compared to the low $B_{12}$ group, however, no difference in mean corpuscular volume was observed between the two groups. The normal $B_{12}$ group showed significantly lower serum homocysteine concentration (p < 0.01) and prevalence of vitamin D (p < 0.01) or folate deficiency (p < 0.001). Bone mineral density (T-score) was significantly higher (p < 0.05) in the normal $B_{12}$ group, compared with that in the low $B_{12}$ group, and showed positive correlation (r = 0.1490, p < 0.01) with serum vitamin $B_{12}$ concentration after adjusting for age, body weight, and body mass index. No differences in anthropometric data, physical activity, and smoking and drinking habits were observed between the two groups. In conclusion, it could be suggested that older female adults with normal serum vitamin $B_{12}$ level would be less anemic and osteoporotic and more resistant to hyperhomocysteinemia associated chronic diseases than those with low serum vitamin $B_{12}$ level.