People who take certain
acid-reflux medications might have an increased risk of vitamin B12
deficiency, according to new research.
Taking proton pump
inhibitors (PPIs) to ease the symptoms of excess stomach acid for more than two
years was linked to a 65% increase in the risk of vitamin B12
deficiency. Commonly used PPI brands include Prilosec, Nexium and Prevacid.
Researchers also found that
using acid-suppressing drugs called histamine-2 receptor antagonists – also
known as H2 blockers – for two years was associated with a 25% increase in the
risk of B12 deficiency. Common brands include Tagamet, Pepcid and Zantac.
Testing for vitamin B
"This study raises the
question of whether or not people who are on long-term acid suppression need to
be tested for vitamin B12 deficiency," said study author Dr Douglas
Corley, a research scientist and gastroenterologist at Kaiser Permanente's
division of research in Oakland, California.
Corley said, however, that
these findings should be confirmed by another study. "It's hard to make a
general clinical recommendation based on one study, even if it is a large
study," he said.
Vitamin B12 is an
important nutrient that helps keep blood and nerve cells healthy, according to
the US Office of Dietary Supplements (ODS). It can be found naturally in
meat, fish, poultry, eggs, milk and other dairy products. According to the ODS,
between 1.5% and 15% of Americans are deficient in B12.
Although most people get
enough B12 from their diet, some have trouble absorbing the vitamin
efficiently. A deficiency of B12 can cause tiredness, weakness, constipation
and a loss of appetite. A more serious deficiency can cause balance problems,
memory difficulties and nerve problems, such as numbness and tingling in the
hands or feet.
Reducing stomach acid
Stomach acid is helpful in
the absorption of B12, Corley said, so it makes sense that taking medications
that reduce the amount of stomach acid would decrease vitamin B12 absorption.
More than 150 million
prescriptions were written for PPIs in 2012, according to background
information included in the study. Both types of medications also are available
in lower doses over the counter.
Corley and his colleagues
reviewed data on nearly 26 000 people who had been diagnosed with a vitamin
B12 deficiency and compared them to almost 185 000 people who didn't have a
While 12% of people
with a vitamin B12 deficiency had taken PPIs for more than two years, 7.2% of those without a deficiency had taken the medications long-term.
Of those with a deficiency,
4.2% took an H2 blocker for two years or longer, while 3.2% of those
without a deficiency took the drugs for two years or more.
The risk of developing a
vitamin B12 deficiency was 65 percent higher for the long-term PPI users and
25 percent higher for those taking H2 blockers, according to the study.
People who took higher
doses were more likely to develop a vitamin B12 deficiency. People who took an
average of 1.5 PPI pills per day had almost double the risk of developing a
deficiency compared to those who averaged 0.75 pills per day, the study found.
Women had a greater risk of
deficiency than men, and people younger than 30 taking these medications had a
greater risk of developing a deficiency than older people, according to the
The risk of vitamin B12
deficiency decreases when you stop taking the medications, but doesn't
disappear completely, Corley said.
The study's findings were
published in the Journal of the American Medical
Association. Although the study found an association between taking
acid-reflux drugs long-term and having a higher risk of a B12 deficiency, it
didn't establish a cause-and-effect relationship.
Lowest effective dose
If you're taking
acid-suppressing medications, Corley said, "our study doesn't recommend
stopping those medications, but you should take them at the lowest effective
dose." And people shouldn't start taking vitamin B12 supplements on their
own, but should discuss it with their doctor, he said.
One expert had concerns
about how frequently acid-suppressing drugs are used.
"This study found an
adverse effect associated with taking these drugs," said Victoria Richards,
an associate professor of medical sciences at the Frank H. Netter M.D. School
of Medicine at Quinnipiac University, in Hamden, Connecticut. "It's also
concerning that these drugs are used at such a high rate. Why do so many people
have the need to suppress acid so much?"
The bottom line, Richards
said, is that if you are having any symptoms of vitamin B12 deficiency and
you've been taking these medications, talk to your doctor about whether you
should be tested for a deficiency. Tell your doctor if you've been taking
over-the-counter acid-suppressing medications, so your doctor can properly
evaluate your risk.
Visit the US Office of
Dietary Supplements to learn more about vitamin