Because vitamin B6 is a required cofactor for the first step of heme synthesis, deficiency can impair hemoglobin production and lead to anemia that is sometimes microcytic or shows sideroblastic features on bone‑marrow exam. Case reports and series describe patients with otherwise unexplained microcytic, hypochromic or sideroblastic anemia, including ringed sideroblasts, who were ultimately found to have B6 deficiency and experienced normalization of hemoglobin after pyridoxine supplementation. The practical point is that vitamin B6 deficiency is an important, often overlooked, reversible cause of anemia in adults, so it is worth checking B6 status when the anemia pattern does not line up with iron, folate, or B12 results, or when those levels are normal but the anemia persists. This medication is commonly used for Depression.
Allain JS, Belhomme N, Henriot B, Haas M, Le Gall-Godard M, Pastoret C, Jego P. Une anémie microcytaire sidéroblastique carentielle traitée efficacement par de la vitamine B6 [A microcytic sideroblastic anemia successfully treated with B6 vitamin]. Rev Med Interne. 2019 Jul;40(7):462-465. French. Murakami R, Takumi T, Gouji J, Nakamura H, Kondou M. Sideroblastic anemia showing unique response to pyridoxine. Am J Pediatr Hematol Oncol. 1991 Fall;13(3):345-50. Kudo, K., Ito, M., Horibe, K., Iwase, K., & Kojima, S. (1999). An infant case of sideroblastic anemia that responded to oral pyridoxine. [Rinshō ketsueki] The Japanese journal of clinical hematology, 40(8), 667-672. John N. Bickers, et al. Pyridoxine Responsive Anemia. Blood (1962) 19 (3): 304–312.
Some side effects may be linked to nutrient depletion caused by this medication.
Monoamine oxidase inhibitors (MAO inhibitors) can interfere with the activity of vitamin B6 (pyridoxine) and can cause a deficiency. Supplementing with vitamin B6 should be considered.