Low or deficient vitamin B12 status is a leading cause of megaloblastic anemia, where impaired DNA synthesis disrupts red blood cell division and produces large, fragile megaloblasts instead of healthy cells. Clinically, vitamin B12–deficiency anemia is relatively common, with some population studies suggesting that up to 10–15% of older adults have biochemical B12 deficiency and a subset of these develop overt megaloblastic changes and anemia. In addition to fatigue and pallor from reduced oxygen‑carrying capacity, patients may show macrocytosis on CBC, elevated methylmalonic acid and homocysteine, and, if unrecognized, can progress to severe anemia that coexists with potentially irreversible neurologic complications This medication is commonly used for Pain Management.
Habeb B, Khair S, Reid A (July 14, 2025) Unmasking Pernicious Anemia: A Reversible Cause of Pancytopenia Due to Severe Vitamin B12 Deficiency. Cureus 17(7): e87911. Lee YP, Loh CH, Hwang MJ, Lin CP. Vitamin B12 deficiency and anemia in 140 Taiwanese female lacto-vegetarians. J Formos Med Assoc. 2021 Nov;120(11):2003-2009. Ankar A, Kumar A. Vitamin B12 Deficiency. 2024 Sep 10. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan–. PMID: 28722952. Wong CW. Vitamin B12 deficiency in the elderly: is it worth screening? Hong Kong Med J. 2015 Apr;21(2):155-64.
Some side effects may be linked to nutrient depletion caused by this medication.
Regular use of aspirin (acetylsalicylic acid) can increase how much vitamin C your body gets rid of through urine, potentially leading to deficiency. If you take aspirin regularly, consider supplementing with vitamin C supplementation.
Research found that individuals hospitalized with heart disease and a history of aspirin use were nearly twice as likely to have low or borderline vitamin B12 levels compared to non-aspirin users. While this doesn't definitively prove aspirin causes B12 deficiency, it raises a potential link. Aspirin can irritate the stomach lining in some individuals. This is concerning because the stomach plays a crucial role in vitamin B12 absorption by producing hydrochloric acid and intrinsic factor. Both are essential for proper B12 uptake.