Neuropathy (nerve disease) is extremely common in diabetics. Typical symptoms include numbness in the feet; tingling, pins and needles or pain. These are such common symptoms in diabetics that they’re almost expected. It is true that high blood sugar is toxic to nerves (and many other organs of the body), but neuropathy isn’t solely due to diabetes. Not every diabetic experiences neuropathy. Certainly there are people with mild, well controlled diabetes who suffer a great deal from nerve pain. An increasing amount of research is showing that vitamin B12 deficiency is extremely common in diabetics, and may be the biggest trigger of nerve problems. Metformin is the most commonly prescribed drug to lower blood sugar. It’s an effective drug with few side effects. However, it does cause vitamin B12 deficiency because it reduces the ability of your body to absorb this vitamin. Metformin reduces the production of bile and intrinsic factor (both necessary for B12 absorption). It also reduces your ability to absorb B12 across the wall of your small intestine (ileum). To add insult to injury, stomach acid suppressing drugs are well known to cause B12 deficiency, and these drugs are widely taken by diabetics. A study was recently published in the journal Clinical Diabetes titled Metformin With Either Histamine H2-Receptor Antagonists or Proton Pump Inhibitors: A Polypharmacy Recipe for Neuropathy via Vitamin B12 Depletion. Histamine H-2 Receptor Antagonists and Proton Pump Inhibitors are the two categories of stomach acid blocking drugs. Common brand names include Zantac, Tagamet, Nexium, Pepcid, Losec, Somac and Zoton. There are a lot of people taking one of these drugs. The combination of one of them with metformin is a recipe for disaster. If you are taking one or both of these drugs, please see your doctor for a vitamin B12 blood test. B12 is naturally found in animal foods such as red meat, poultry and seafood, but if you are suffering with nerve problems you will need a supplement. It’s sad that a lot of people suffer terribly from neuropathy which could easily be prevented. Source: Zdilla MJ. Metformin With Either Histamine H2-Receptor Antagonists or Proton Pump Inhibitors: A Polypharmacy Recipe for Neuropathy via Vitamin B12 Depletion. Clinical Diabetes. 2015; 33(2): 90-95.