Low or depleted vitamin B12 status can worsen gastrointestinal problems by impairing mucosal repair and driving malabsorption in conditions such as Crohn’s disease, celiac disease, and small intestinal bacterial overgrowth, where inflammation, resections, and dysbiosis limit B12 uptake. Reduced B12 also weakens white blood cell production and immune defenses, increasing susceptibility to bacterial, viral, and fungal infections that further destabilize gut balance and make it even harder to restore adequate B12 levels. This medication is commonly used for Diabetes.
Akbulut S. An assessment of serum vitamin B12 and folate in patients with Crohn's disease. Medicine (Baltimore). 2022 Dec 16;101(50):e31892. Trimarchi H, Forrester M, Schropp J, Pereyra H, Freixas EA. Low initial vitamin B12 levels in Helicobacter pylori--positive patients on chronic hemodialysis. Nephron Clin Pract. 2004;96(1):c28-32. www.jcimcr.org Page 2 Citation: Andrès E, Lorenzo-Villalba N. Maldigestion and malabsorption of cobalamins (Vitamin B12): Mechanisms, clinical spectrum, at-risk populations, and therapeutic approaches. J Clin Images Med Case Rep. 2025; 6(11): 3841.
Some side effects may be linked to nutrient depletion caused by this medication.
Long term treatment with Biguanides, such as Metformin or Metformin combinations with other drugs, are found in research to reduce vitamin B12 absorption due to it hindering the activity of a calcium-dependent mechanism. Insufficient levels of vitamin B12 can lead to higher circulating homocysteine levels and the elevated risk of neurological problems and cardiovascular diseases.
Biguanide (anti-diabetic) drugs have been found in scientific evidence to decrease serum levels of coenzyme Q10. Type 2 diabetes can increase oxidative stress in the body, weakening its defenses and potentially harming cells. CoQ10, a powerful antioxidant, plays a crucial role in protecting cells from this damage. CoQ10 supplementation may help restore these levels, potentially improving mitochondrial function and protecting the kidneys from damage.
Research has shown that anti-diabetic Biguanide drugs may reduce folic acid absorption. Folic acid is a powerful antioxidant and low levels make the body more susceptible to oxidative stress, which can damage enzymes involved in homocysteine metabolism, and subsequently increase its accumulation. Elevated levels of homocysteine (hyperhomocysteinemia) are a risk factor for various health problems including cardiovascular diseases, neurological problems, osteoporosis, and vision problems.
Biguanides, such as Metformin or Metformin combinations with other drugs, may contribute to reduced levels of thiamine (vitamin B1) in end-stage renal failure patients. Research has found metformin encephalopathy present in patients on hemodialysis for end-stage diabetic renal failure (ESRD). Patients with ESRD should consider having thiamine (vitamin B1) status monitored and supplementing with thiamine when levels are insufficient or deficient.