Are B Vitamin Supplements Increasing Your Stress & Anxiety?

It’s interesting that B vitamin supplements are often labeled as “stress complex“. I think it would be more accurate to label B vitamins as “energy complex” due to their critical role in energy production. While some people who do have an improved stress response when taking a B supplement, I have seen a number of patients who become more stressed and anxious when taking B vitamins. Most people that experience negative side-effects from B Vitamins are completely unaware that a “stress complex” could actually making their anxiety worse. In this post I will do my best to explain why B vitamins sometimes help and sometimes hurt.

(Note that this article will use the terms “B vitamin” or “B complex” to refer only to high-dose B Vitamin supplements. Specifically, we are talking about B vitamin supplements or multivitamins that supply many times the RDA amount for a variety of B vitamins. For example a common supplemental dose of Vitamin B12 is 400 mcg – which is 16,667% of the RDA’s “Recommended Daily Value”.)

Most articles and books on the topic of B vitamins simply says that everyone needs more… right?  The more B’s the better?  The vast majority of the articles I see online seem to suggest that everyone would benefit from a high-dose B Complex, and that high doses are safe and effective for everyone. Over the last 15 years my clinical experience has shown that this is not the case. I have repeatedly seen patients that have anxiety, panic attacks and sleep problems that are worsened by taking high-dose B vitamins, and dramatically improved when they stop taking B vitamins. I have even seen cases where patients are taking such high doses of B vitamins that their respiration is effected and their Western doctors are suggesting surgery to fix “their sinus problem”! That being said, most people will actually experience no negative effects when taking a B Complex for long-term, but the point here is that there is a (small) percentage of the population that will have negative side effects.

To explain why excess B vitamins sometimes have negative side effects (most commonly anxiety and insomnia), we will need to consider the basics. B vitamins, of course, are essential nutrients for the human body. Without having all of the B vitamins in adequate quantities deficiency diseases will gradually develop. For example, B1 deficiency leads to a disease called beriberi, B2 deficiency results in ariboflavinosis, B3 deficiency leads to pellagra, etc. One way to look at all the diseases of B vitamin deficiency is to say that they are all a loss of fundamental cellular function, meaning the cells no longer have enough cellular energy to maintain health. Most of the B vitamins are directly involved in the production of energy from food. Do you remember the “Krebs cycle” of energy production we learned in high school biology class?  Honestly the Krebs cycle is a complicated mess of inputs and outputs with the ultimate goal being the generation of energy as ATP.  Without B vitamins present as “coenzymes” none of this energy production magic can work.  These “coenzymes” to push the energy production system forward by acting as catalysts to various chemical reactions in the cells (in the mitochondria, actually).

I don’t want to get lost in the science here, but the basic idea is that B vitamins are the magic molecules that unlock energy production from our food.  As such, many people will benefit from having improved energy production.  And “common knowledge” says that we can take large doses of B vitamins and the body will just discard any excess, so there’s no harm in taking large doses daily, right?  For most people this is true, but I have found that for people who are prone to anxiety and sleep difficulty (usually people with more “sensitive” constitutions) excess load for B vitamins can start to create negative side effects.  For this case it seems like the excess B vitamins are ramping up energy production system in person who already has enough cellular energy.  It is possible that these “sensitive types” may be so good at creating cellular energy that they are already feeling stressed, anxious and having difficulty sleeping.

Why are some people sensitive to B vitamins while others can take them in high doses for years without issue? We don’t know the exact answer, but it seems like there are a range of genetic differences that effect certain metabolic pathways. For example, we do know that individuals with a “COMT mutation” may be more sensitive to high doses of B vitamins. These COMT mutations slow down the activity of the COMT enzyme, can cause dopamine excess imbalances.  For this case high levels of B vitamins can worsen the dopamine imbalance and therefore cause some of the symptoms discussed above.

Below is a summary of how a few B vitamins could be having negative effects:

B6
Vitamin B6 is added to thousands of supplements, including multivitamins, B vitamins and energy drinks.  B6 can increase the production and release of various stimulating neurotransmitters including norepinephrine (noradrenaline) and dopamine. While this energizing is usually a welcome effect, problems can occur when the dose of B6 is too high, especially when it is too high relative to other B vitamins. Excess vitamin B6 can increase the likelihood of side effects such as anxiety, irritability, restlessness and sometimes numbness in the extremities.

B12
B12 is a very popular supplement for energy and vitality.  In the US many people are actually deficient in B12, especially older populations. However, like vitamin B6, higher doses of B12 are know to increase neurotransmitter levels, acting as a stimulant. In this way B12 can be beneficial for people with mood disorders like depression, but in excess it can result anxiety, worry, restlessness, and sleep problems.

Hopefully giving two specific examples above (B6 and B12) is helpful to illustrate my point.  There are still more B vitamins that can create metabolic problems including B1, B2 and Folate (B9) but I will spare you the details on each specific one.

In summary, all B vitamins are metabolic “activators” so it is good practice to start with a low dose monitor for changes over the following days and weeks when adding a new supplement.  One of the difficulties with recognizing problems from excess B vitamins is that the symptoms tend to gradually increase over weeks.  Occasionally people will experience acute reactions to a B vitamin, but this is not common, instead symptoms usually worsen over time while taking a supplement daily.  This makes it more difficult to identify the culprit, but with a bit of experimentation and vigilance it will become obvious if there is a problem.  Also note that when removing a B vitamin supplement the negative symptoms will gradually decrease over weeks; here again, it is very unusual to stop taking a B supplement one or two days and notice much of a difference.  But over the course of weeks it will become more clear.

As a final note, keep in mind that manufacturers love to put B vitamins in EVERYTHING these days, including: bread, snacks, almond milk, soy milk, electrolyte powders, packaged drinks, etc.  So if you are sensitive to B vitamins you may even have to look out for all of these other sources as well.  Over the course of a day if you have a number of these food and drink items the dose could easily build up and cause problems.