Vitamin B12 – Can it Help You Lose Weight?


Essential for cell metabolism, vitamin B12 is involved in the processing of energy from protein and fat. While its use as a treatment for a certain kind of anemia is well established, it is also marketed in other ways. One of these is as a weight loss supplement. But does it work? Are people actually losing weight with this stuff? In this article we’ll take a look at some of the myths, truths, and unknowns of vitamin B12 and weight loss.

First, what the heck is it, exactly?

Vitamin B12, chemically known as cyanocobalamin, is found in animal products like meat and eggs and is involved in the conversion of energy in the cells. To be absorbed by the human body, it must go through a complicated “assembly line” involving two stomach chemicals, the pancreas, and the small intestines. A malfunction in any of these from a disease like, say, irritable bowel syndrome can cause a deficiency in B12. But that’s another story. Vitamin B12 is available as a supplement in pill or injection form, and is sometimes touted as a weight loss aid.

Unfortunately, there just isn’t much in the way of published scientific evidence. The famous Mayo Clinic says on its website that “there is no evidence that vitamin B-12 in any form — including vitamin B-12 injections — enhances weight loss.” It then goes on to mention only one study done in 2005 that showed vitamin B12 users gained weight slightly slower than non-users over the course of many years. Straight from the mouth of the highest health authority on the planet? So is that it, then? Nothing else to say?

Well, not so fast.

While it’s good to hold scientific evidence in high regard, it certainly can’t hurt to look at some anecdotal “evidence” as well. Some scientific studies are notoriously poorly designed. And news right from public opinion can occasionally be useful. Keep in mind, however, that weight loss is extremely difficult to judge as there are so many factors involved. Could be the person started jogging just a little bit faster without realizing it, but thinks the B12 is responsible.

OK, let’s take a look at a weight loss discussion forum and see what people are saying. On, a user asked if vitamin B12 does actually help with weight loss at all, and got several responses. One member said that her doctor told her B12 helps reduce water retention and improves energy levels, but does not directly help you lose weight. Another said he takes B12 shots for a B12 deficiency-related condition, and they did not help him lose weight. The consensus in this discussion thread seems to be that the vitamin does help increase energy levels and thus may help people exercise a bit more vigorously.

Let’s look at another one. On the forums at, a member asks a similar question. Many of the responses were also similar. One user said he was taking B12 shots for years and loved the way they made him feel. Several other users reported similar results, and most agreed they did not seem to directly help with any weight loss.

One more. is a large site that offers consumer reviews of almost everything. A quick look at the reviews for vitamin B12 shows many people, again, reporting increased energy and just a better overall feeling after taking them. No one mentions any effect on weight loss, however.

So did we learn anything?

Well, since the scientific evidence is so thin, it’s almost impossible to come to any definite conclusions. A look at B12 use on “the street” seems to show a lack of much anecdotal weight loss evidence, but quite a bit of reports of “increased energy.” There just doesn’t seem to be much support for it as a weight loss supplement. However, B12 may be useful as an energy enhancer and if you are in a risk category for B12 deficiency, such as a sufferer of irritable bowel syndrome and other stomach ailments, or a vegetarian who does not eat much dairy. If you are going to take B12, please look for a B complex instead of B12 just by itself as the B family works together much better than separately.

Source by Alan Glender