The American Diabetes Association’s thorough review states that everybody hundreds of millions of careless men do take Metformin across the world which has a great effect on absorption of vitamin B12. Their observations indicate that 20 to 30% of patients on Metformin developed B12 deficiency four years of treatment after starting this drug. Moreover, some antihypertensive agents which are given to diabetic patients may cause malabsorption of certain minerals such as calcium and magnesium which perform an important role for the nerves.