Vitamin B12 deficiency linked to cardiovascular disease

A recent narrative review published in the Nutrition Journal indicates that while low vitamin B12 levels are associated with cardiovascular disease, taking supplements does not consistently lead to a long-term reduction in major cardiovascular events.

Vitamin B12, found naturally in animal products like meat, fish, eggs, and dairy, is essential for enzyme functions that regulate homocysteine and methylmalonic acid (MMA). A deficiency can lead to the buildup of these substances, potentially causing oxidative stress, endothelial dysfunction, and atherosclerosis.

Research suggests the most significant clinical benefit may come from combined B-vitamin therapy for stroke prevention, particularly in populations where food is not mandatorily fortified with folic acid. However, large-scale studies, including a Cochrane review of over 71,000 participants and trials such as NORVIT and HOPE-2, have not found a significant reduction in heart attacks or overall cardiovascular mortality through supplementation.