Vitamin B12 deficiency may be induced by long-term use of Metformin - a medication used to treat type 2 diabetes. This in turn may lead to elevated homocysteine levels (hyperhomocysteinemia).1 Hyperhomocysteinemia may increase the risk of blood clots in diabetic patients, when metformin is used and a homozygous MTHFR C677T mutation is present.[1, 3]
Hyperhomocysteinemia can cause irritation of the blood vessels, possibly increasing risk for hardening of the arteries, heart attacks, stroke, and blood clots in the veins (venous thrombosis). Elevated homocysteine levels can be caused by deficiency of B vitamins and folate in the diet and by a double mutation in the 677TT variant of the MTHFR gene.
People carrying the MTHFR 677TT genotype have higher folate and vitamin B12 requirements.3
Related to:
Vitamin B12, Folate, MTHFR gene, Homocysteine