Aspirin can affect this through 2 different nutrient pathways: Folic Acid, Vitamin B12. This medication is commonly used for Pain Management.
Each nutrient below contributes to this impact through a different mechanism.
Folate (folic acid) deficiency impairs DNA synthesis in rapidly dividing cells, which leads to megaloblastic anemia characterized by enlarged red blood cells, fatigue, pallor, and sometimes shortness of breath. Population studies have shown that folate deficiency and macrocytosis can be present for months before overt symptoms appear, and in some cohorts, up to roughly one quarter of anemic adults had an underlying folate or B12 deficiency rather than iron deficiency alone. The encouraging clinical point is that, once identified, folate‑responsive megaloblastic anemia often improves within weeks of adequate folic acid repletion, with reticulocyte counts rising in about 5–7 days and hemoglobin recovering more gradually over several weeks.
Koury MJ, Price JO, Hicks GG. Apoptosis in megaloblastic anemia occurs during DNA synthesis by a p53-independent, nucleoside-reversible mechanism. Blood. 2000 Nov 1;96(9):3249-55. Daniel S. Socha, MD, Sherwin I. DeSouza, MD, Aron Flagg, MD, Mikkael Sekeres, MD, MS and Heesun J. Rogers, MD, PhD. Severe megaloblastic anemia: Vitamin deficiency and other causes. Cleveland Clinic Journal of Medicine March 2020, 87 (3) 153-164. H.B. Castellanos-Sinco, et al. Megaloblastic anaemia: Folic acid and vitamin B12 metabolism. Revista Médica del Hospital General de México. Vol. 78. Issue 3. Pages 105-150 (July - September 2015). Anis Hariz, et al. Megaloblastic Anemia. StatPearls April 3, 2023.
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
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 aspirin use, even at therapeutic doses, can lead to lower-than-normal levels of folate in the blood (serum folate). Additionally, aspirin might slightly increase the amount of folate excreted in urine, potentially disrupting the body's folate balance. For those taking regular aspirin therapy, folic acid supplementation should be considered to prevent a deficiency.
Studies indicate that medications like aspirin can increase zinc loss through urine. Zinc plays a vital role in wound healing, protein synthesis, cell reproduction, immunity, and vision. If you take aspirin regularly, consider monitoring zinc levels and supplementation may be beneficial to prevent a deficiency.
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.