Vitamin B12 absorption test and oral treatment in 14 children with selective vitamin B12 malabsorption

Oral vitamin B (VB12) absorption was studied in 12 patients with selective VB12 malabsorp12 tion and in 6 age-matched healthy controls. Serum VB12 level was measured before and 3 h after oral administration of VB12 100 or 1000 mu g . After administration of 1000 mu g of VB12 an appreciable increase in the serum VB12 level was observed in patients as well as in controls. The mean of the increase in serum VB12 level did not differ between patients and the controls (273 203 pg/mL, 180 71 pg/mL, respectively P > . 05 ). Twelve patients previously treated by parenteral VB12 were switched to, and 2 newly diagnosed patients were started on, oral VB12 treatment of 1000 mu g given every 2 weeks. Hematological parameters and serum VB12 levels remained stable after switching to oral therapy in the 12 patients. In the two newly diagnosed patients anemia was cured by orally administrated VB12. This study lends further support to the use of megadoses of VB12 as an alternative treatment for selective VB12 malabsorption.