[Early response to oral cobalamin therapy in older patients with vitamin B12 deficiency].

Purpose: Standard treatment of vitamin B12 deficiency involves regular intramuscular cobalamin administration. The aim of this study was to determine whether oral cobalamin treatment may be an effective therapy for treating older patients with cobalamin deficiency related to nutritional deficiency and food-cobalamin malabsorption.

Patients and methods: We prospectively studied 20 patients older than 80 years with established cobalamin deficiency related to food-cobalamin malabsorption (n=14) and nutritional deficiency (n=6) who received 1000 micro g of oral cyanocobalamin per day. Levels of serum cobalamin and blood counts were determined at baseline and after the first week of treatment.

Results: After an average of 8 days of treatment, 17 out of 20 patients normalized their serum cobalamin levels; the patients had increased their serum cobalamin level (mean increase of 0.23 micro g/L; p<0.01 compared with baseline), reticulocyte count (mean increase of 27400/mm(3); p<0.05), hemoglobin levels (mean increase of 0.7 g/dL; NS), and decreased the mean erythrocyte volume (mean decrease of 0.7 fL; NS).

Conclusion: Our findings suggest that cyanocobalamin given orally during one week may be an effective treatment for cobalamin deficiency related to food-cobalamin malabsorption and nutritional deficiency and may avoid painful intra-muscular injections in older patients.