Rapid Rx Quiz: Vitamin B12

Mary L. Windle, PharmD


October 31, 2022

Before cobalamin treatment, several evaluations are necessary, including reticulocyte count. Other evaluations include serum vitamin B12, iron, hematocrit, and folate counts. Effective therapy can reverse some laboratory abnormalities rapidly, sometimes within 24 hours. The normal bone marrow hematopoiesis may be reestablished within 48 hours, and the reticulocyte count may increase after 3-4 days and reach its peak level after 1 week. Within approximately 8 weeks, a complete blood count may become normal. Compliance with cobalamin supplementation should be monitored in patients with vitamin B12 deficiency. If methylmalonic acid or homocysteine levels fail to return to normal during the first week of treatment, an incorrect diagnosis should be suspected.

Learn more about reticulocyte count.


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