It’s a well-established fact that excessive alcohol consumption and alcoholism are risk factors for vitamin B12 deficiency. Far less research studying the effects of moderate drinking on B12 absorption has been done, but what little there is suggests that the impacts are much the same, just heavily toned down.
Having said that, high alcohol intake over a period of just two weeks can cause a noticeable decrease in the amount of B12 absorbed from the gastrointestinal tract.
Why Alcohol Affects B12 Absorption
Alcohol is known to damage the stomach lining, which can lead to stomach inflammation, a condition known in medical circles as atrophic gastritis. In patients suffering from atrophic gastritis, the stomach cells are no longer able to produce and secrete an important protein called intrinsic factor (IF). Unfortunately, IF is absolutely essential for the absorption of vitamin B12.
Another effect of gastritis is decreased hydochloric acid production. This makes it harder for your body to break down food to get at the all-important B12 molecules in the first place, but there’s also another less obvious problem. Lower levels of hydrochloric acid will actually encourage the growth of certain bacteria in the intestines, some of which use vitamin B12 for themselves. Of course, if they’re using it as well, then there’s less available for you.
Does Alcohol Have Any Other Effects on Vitamin B12?
The National Institute on Alcohol Abuse and Alcoholism also notes that alcohol consumption changes the way in which many nutrients (including B12) are transported and stored in the body, as well as how they are excreted. This can also be problematic, as it prevents some of these nutrients from being fully utilized by the body.
The Effects of Alcohol on Diet
Of course before any of these alcohol-induced effects take their toll, you have to actually ingest food that contains B12, like meat, dairy or specially fortified foods. It is statistically much less likely that alcoholics will eat a healthy and varied diet than it is for people who only consume alcohol in moderation (or not at all).
There are two key reasons for this. The first is that alcohol generally contains a lot of calories. Sadly though, they tend to be empty calories – they don’t have any nutritional benefit. But despite this lack of nutrition, alcohol can still help to fill you up, suppressing your appetite and making you less inclined to eat a healthy meal that would hopefully contain some B12. Some people also end up completely replacing meals with nothing but alcohol – not a good position to be in.
The second reason is that your decision-making skills are impaired by alcohol, an unfortunate effect that most of us are all too aware of. It might not be at the top of your list of drunken mistakes, but the inability to make healthy food choices can have serious consequences over time.
The Effects of Alcohol on Folate
Finally, high levels of alcohol consumption can also put you at risk of folate deficiency. This is relevant as folate (aka folic acid or vitamin B9) is very closely linked to vitamin B12. (We’ve got a whole article on this here if you’re interested.)
The causes of folate deficiency in alcoholics are mostly the same as for B12 deficiency – poor diet, impaired absorption in the gut etc. One additional reason is that acute liver damage can cause excessive urination, carrying more folate out of the body than it would in healthy people.
What You Should Do
If you are suffering from alcohol abuse, taking dietary supplements may well help to improve your health. But the most important thing is to see a doctor and seek professional help. Contacting Alcoholics Anonymous would be an excellent first step to start turning your life around, and their famous ‘Big Book’ has saved many lives.
Top image courtesy of digitalart and FreeDigitalPhotos.net. Second image courtesy of Surachai and FreeDigitalPhotos.net