The epidemic of vitamin B12 deficiency is being driven, in part, by commonly prescribed prescription medications that interfere with B12 absorption and utilization in the body.

The absorption of vitamin B12 from food depends on having proper stomach acid.

Inadequate stomach acid production or medication that blocks stomach acid production will guarantee vitamin B12 deficiency.

Acid-blocking medications are some of the most commonly prescribed drugs in the U.S. More than $13 billion dollars are spent on the most common ones — a class of drugs called proton pump inhibitors (PPIs), such as Nexium or Prilosec.

These medications function by shutting off acid production in the stomach. Although they are only indicated for short-term use, many patients are given long-term treatment with PPIs.

Similarly, over-the-counter antacid medications function to raise the pH of the stomach; their long-term use will also result in B12 deficiency.