Vitamin B12 and PPIs
Will taking anti-reflux drugs make you deficient in vitamin B12? A recent article suggests that they could.
According to this research, patients who took PPIs (proton pump inhibitors) for more than 2 years had a 65% increase in vitamin B12 deficiency. The H2 inhibitors (for example, ranitidine [Zantac]) also increase risk but not as much as the PPIs.
This sounds scary. Vitamin B12 deficiency can be serious.
But don’t panic and throw-out your antireflux drugs without investigating further.
They’re using a type of statistics that can magnify a small effect. For example, let’s say the risk of something in your age group is 2%. You have a 65% increased risk. That means your risk is 3.3%. Greater, yes, but still relatively low.
Metformin can also contribute to vitamin B12deficiency. This has been known since before I was diagnosed in 1996. In fact, the effect of the PPIs on B12 deficiency has also been known for some time, as mentioned in this article from 2011. The Science Daily press release issued by Kaiser Permanente makes it sound as if it’s something new.
Some have estimated vitamin B12 deficiency at 15% in the general population, 30% in those older than 50 years, and 30% in those taking metformin. So the risk is real in those of us who are old geezers even if we’re not taking PPIs, especially when we have diabetes. If you’re over 50 and take both metformin and a PPI, your risk would be greater.
Interestingly, I’m well over 50 and taking both metformin and a PPI, and when my endocrinologist had my B12 levels tested twice, they came out above the top of the normal range. Maybe it’s because I eat red meat regularly, although not humongous amounts. Or maybe they were both faulty tests; this does happen. But this is an illustration of the fact that some effect that applies to a percentage of the population as a whole doesn’t necessarily apply to everyone.
What this suggests is that the results of studies like this are just suggestions of what could happen if your regimen matches that in some study. Rather than rushing out and buying B12 supplements (which are generic and not expensive), it makes sense to have your B12 levels tested first. Although the water-soluble vitamin is not considered toxic in recommended doses, high levels could cause problems in some patients, such as those with coronary stents. The Kaiser article does recommend that people taking PPIs be screened for B12 deficiency, not that they be put on supplements right away.
In general, the same principle applies to any substance you read about in the popular press. The article may alert you to a possible benefit or harm from some food or supplement. But don’t go overboard without seeing whether it really applies to you.