December 11, 2013
News Review From Harvard Medical School -- Acid Blockers Linked with B12 Deficiency
People who take drugs to prevent acid reflux may have a higher risk of vitamin B12 deficiency, a new study finds. The study compared data on 2 groups of people. Nearly 26,000 had a vitamin B12 deficiency. The other 185,000 did not. About 12% of those with low vitamin B12 had taken drugs called proton pump inhibitors for more than 2 years. These are the most powerful drugs to prevent acid reflux. They include lansoprazole (Prevacid), esomeprazole (Nexium) and omeprazole (Prilosec). Among those with normal vitamin B12 levels, only 7.2% took these drugs. That means the long-term users of the medicines had a 65% higher risk of vitamin B12 deficiency. Risk was about 25% higher for people who took different anti-reflux drugs, known as H2 blockers. The study only shows a link between these drugs and low vitamin B12. It does not prove that one causes the other. The Journal of the American Medical Association published the study. HealthDay News wrote about it December 10.
By Howard LeWine, M.D.
Harvard Medical School
What Is the Doctor's Reaction?
Stomach acid is natural and plays an important role in normal digestion. But in excess or in the wrong place, it can cause discomfort and sometimes severe problems. Acid that moves up instead of down gets into the esophagus. The result is irritation that causes heartburn. Even in the right places, too much acid, combined with other factors, can lead to stomach and intestinal ulcers.
Nothing is stronger at blocking stomach acid production than proton pump inhibitors (PPIs). They work by blocking certain stomach cells from "pumping" acid into the stomach. Prescription-only PPIs include esomeprazole (Nexium), pantoprazole (Protonix) and rabeprazole (Aciphex). Some PPIs are also available over the counter. They include lansoprazole (Prevacid) and omeprazole (Prilosec).
Proton pump inhibitors are the best drugs to relieve lasting acid reflux. And they are an essential component of peptic ulcer treatment.
They are generally safe when used in the short term. But they carry some risks in the long term. There has always been concern that proton pump inhibitors could cause B12 deficiency. Stomach acid helps release vitamin B12 from food. That makes it easier to absorb.
Vitamin B12 deficiency can lead to major health problems. They include anemia and nervous system conditions, such as dementia.
Previous studies looking at the link between long-term PPI use and B12 deficiency have not reached clear conclusions. This new, very large study confirms that using high-dose PPIs for two or more years is indeed linked with an increased risk of vitamin B12 deficiency. But the results only suggest a relationship. They do not prove that these drugs directly cause B12 deficiency.
Vitamin B12 deficiency is only one of the concerns of long-term use of proton pump inhibitors. Other problems include the potential for:
- Decreased absorption of iron and calcium
- Thin bones that may increase the risk of osteoporosis and fractures
- A higher risk of pneumonia and diarrhea caused by Clostridium difficile bacteria
What Changes Can I Make Now?
By far and away, the most common reason people take a proton pump inhibitor is to relieve the heartburn from acid reflux. It's easier to pop a pill than to make lifestyle changes. But these changes can greatly reduce and often eliminate acid reflux:
- Lose weight if needed.
- Avoid foods that trigger your symptoms, such as spicy dishes or chocolate.
- Eat smaller meals, and eat more often.
- Don't lie down within three hours after a meal.
- Don't smoke.
If you take a proton pump inhibitor and your heartburn symptoms are under control, talk with your doctor about step-down therapy. For example, take a lower PPI dose in the morning. Then take a different acid inhibitor, called an H2 blocker, at night. You can buy many H2 blockers over-the-counter. They include ranitidine, famotidine and nizatidine.
The next step would be to stop the PPI and take the H2 blocker twice a day. Then, with lifestyle changes, you may need the H2 blocker only once per day or only when heartburn occurs.
Some people probably should not abandon their PPIs:
- People with ulcers who also take aspirin for heart protection
- People with lasting, severe inflammation of the esophagus (esophagitis)
In these cases, the benefits of a PPI generally outweigh the risks. But making that decision depends on your health status and any factors that might increase your risk. Discuss all of this with your doctor.
What Can I Expect Looking to the Future?
Experts currently don't recommend routine blood testing for B12 deficiency in people on long-term PPI therapy. More studies looking at this question will surely be done.
Meanwhile, if you take a proton pump inhibitor regularly and have fatigue or any neurological symptoms, it's surely reasonable to ask your doctor for a blood test to check your vitamin B12 level.