Is Your B-Complex Vitamin Doing More Harm Than Good?

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Supplementing with a B-complex can be a valuable addition to your healthy diet and lifestyle. But choosing the wrong one for your unique needs may prevent you from reaping all the benefits.

Choosing the right B-complex vitamin for you isn’t as easy as picking any supplement off the store shelves. There are unique properties to these vitamins that make choosing one somewhat complex. You’ll likely need more research and understanding of your own body to find the right one for you.

The symptoms of B-vitamin deficiency range from anemia and digestion issues, to muscle weakness and poor memory. B-vitamins are definitely vital nutrients that we need to ensure we’re getting enough of.

And even if your diet is full of B-vitamin rich foods like meat, fish, shellfish, eggs, beans, and veggies, you might be part of the population that still needs to supplement.

In this article, you’ll learn:

  • Who likely needs to supplement with a B-complex
  • The main issues with taking any vitamin B-complex
  • My recommendations for the best brands to take depending on your health needs


Who Needs to Take a B-Complex

A whole foods diet with lots of variety (including many different types of both plants and animals) is usually enough to keep most people healthy and not need the use of many supplements.

But, even with the healthiest diet, there are still many reasons why someone may need to use a B-complex.

Here are a few reasons why you might want to consider adding a high-quality B-complex into your routine.

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If You Have Certain Gene Mutations

There are certain genetic mutations (you’ve probably at least heard of the most common one, MTHFR) that may make you a good candidate for supplementing with a B-complex.

Specifically, gene mutations that affect your methylation processes need extra attention to the type and amount of B-vitamins you’re supplementing with.

Methylation is a biochemical process that occurs in every cell in our bodies. This process enables our bodies to regulate and express certain genes, detoxify, metabolize hormones, build immune cells, and so much more.

Chris Kresser has a great podcast all about methylation if you want to dig deeper into this topic.

But, if you think you might fall into this category of someone with methylation issues, I recommend you get your genetics tested.

This will help you understand exactly what genetic mutations are behind your body’s inability to methylate, and will inform your decisions around how to supplement with B-vitamins.

You can use a service like 23AndMe to determine your genetic makeup, and then you can input your data into GeneticGenie for a free PDF that will show you your unique methylation and detox capabilities.

Once you’re armed with that data, you can then work with a healthcare provider to determine how you should use a B-complex supplement to best support your health.

Here are three of the most common genetic mutations that require special attention to the type and quality of B-complex supplements that are used.

If You Have an MTHFR Mutation

The MTHFR enzyme metabolizes folic acid into 5-MTHF. We need 5-MTHF to metabolize homocysteine and to facilitate methylation processes.

With one or more defects in this gene, the enzyme works slower and thus allows homocysteine to build up. The buildup of homocysteine may increase the risk of heart disease and stroke.

A poorly functioning MTHFR enzyme also limits a person’s methylation capacity.

With reduced methylation capacity your body is less able to break down compounds like histamine, serotonin, and dopamine. It also may prevent the proper regulation of gene expression.

This means with an MTHFR mutation, you’re more likely to suffer from mental illnesses like schizophrenia, depression, and bipolar disorder, as well as autoimmune disease, ADD, autism, spina bifida, Down’s syndrome, miscarriages, and cancer.

But don’t let this scare you. Our genes don’t have the final say. By living a lifestyle conducive to good health (eating whole foods, exercising, not smoking, etc.) we can override much of our genetic destiny.

The primary treatment for this specific mutation is supplementing with high-quality forms of folate, B12, B6, and choline avoiding processed fortified foods, and making sure not to over supplement.

Those with the MTHFR SNP need to avoid folic acid and supplement instead with an active form of folate, specifically 5-Methyltetrahydrofolate (5-MTHF).

Talk to your personal healthcare provider about specific dosage recommendations.

If You Have a COMT Mutation

A COMT mutation is another commonly seen genetic defect that affects a person’s methylation functions, but in a different way than the MTHFR mutation.

The COMT enzyme degrades catecholamines such as dopamine, epinephrine, and norepinephrine.

When the COMT enzyme isn’t working, as is common with this mutation, these catecholamines can build up. In excess, these chemicals can be stimulating to the nervous system, promoting anxiety, mood swings, and possibly leading to disorders like schizophrenia and bipolar, or even Parkinson’s disease.

People with a COMT mutation (particularly homozygous) often need to limit or avoid supplementing with methyl donors. As methyl groups tend to build up, they lead to overmethylation symptoms like irritability, anxiety, insomnia, migraines, nausea, and more.

Those with COMT mutations may need to limit their intake of methylated folate (check out folinic acid), and use hydroxycobalamin or adenosylcobalamin rather than methylcobalamin as a B12 supplement.

If You Have a CBS Mutation

We must address the CBS genetic defect before starting an MTHFR treatment.

The CBS enzyme converts homocysteine to cystathionine and removes sulfur-containing amino acids. Thus those with a CBS mutation are sensitive to high dietary sulfur intake, as well as vitamin B6.

There is a long process required to help clear excess sulfur in those with CBS issues. This includes dietary restrictions and a variety of supplements.

I recommend anyone with a homozygous CBS mutation to seek guidance from a health professional well-versed in treating this mutation, as it’s one of the more complicated defects to manage.

As you can see, defects in your methylation enzymes can have an enormous effect on your health, as well as the appropriateness of taking a B-vitamin complex.

If you’ve ever had a negative reaction to a B-Complex, consider the possibility that you have one or more of these genetic issues and get your genome tested to make sure!

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If You’re a Vegan or Vegetarian

Plant foods do not contain vitamin B12. And while beans and legumes do contain a decent amount of folate, without consuming any animal products, you’re not giving your body the complete B-vitamin profile that it needs.

If you’re on a vegan or vegetarian diet, supplementing with a high-quality B-complex (especially B12) is the best way to ensure you won’t become deficient in these essential vitamins.

We add B-vitamins to many foods, like bread, nut milk, and meat substitutes. But you can’t be certain of the quality of these added vitamins, which are usually synthetic. They’re usually not the highest quality versions of these vitamins and it’s best that we avoid or limit them when possible.

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If You’re Pregnant or Breastfeeding

The primary population that should supplement with high-quality B-vitamins are women who are pregnant, looking to become pregnant, or breastfeeding.

The biggest reason why B-vitamin supplementation is so important during this time is to ensure adequate folate intake. Folate is the primary nutrient shown to protect against neural tube defects (NTDs) and promote healthy neurological development in unborn and newborn babies.

But folate isn’t the only issue when it comes to a baby’s brain health. Choline and vitamin B12 are also related to the risk of NTDs and are crucial for proper fetal brain development.

Deficiencies of these B-vitamins during pregnancy are also associated with insulin resistance, increased adiposity (e.g. “fatness”), and reduced cognitive function in the offspring of those mothers who were deficient.

It’s important to ensure you’re getting enough of all these critical B-vitamins while you’re pregnant or breastfeeding. Some ways to do this are:

  • consume eggs at least 2-3 times a week
  • make sure you’re supplementing with a whole food prenatal that includes folate, B12, and choline

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If You Drink (or Used to Drink) A Lot

One last population that definitely needs a B-vitamin supplement is people who consume more than 1-2 alcoholic drinks a day or have a history of alcoholism.

Those who drink excessive amounts of alcohol are at risk for deficiencies in nearly all the B-vitamins. But thiamin (B1), B12, B6, and folate deficiencies are particularly well-evidenced issues for people who have a history of consuming excessive amounts of alcohol.

Anyone who is currently drinking more than the recommended 1-2 alcoholic drinks per day, or who has a history of alcoholism, should take a high-quality B-Complex.

This will help to address any lingering nutrient deficiencies that exist and prevent some of the neurological damage that can come from long-term alcohol abuse.

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Why You Should Be Picky About Your B-Complex

We should care about the quality of the supplements we put in our bodies as much or even more than the quality of the food we eat.

And unfortunately, not all B-complex supplements are created equal.

Supplements provide targeted support at higher doses than what your body normally gets through everyday food consumption. So it’s important that the nutrients you’re giving it through supplementation are the highest quality and are right for your unique needs.

This is why choosing a B-complex is more involved than grabbing one off the store’s shelves. Without doing proper research into both the supplement and your own specific needs, it’s likely that you’ll be wasting your money on pills that aren’t truly beneficial. And in some cases, the wrong supplement can be harmful.

Here are some of the main issues that I see with most generic B-complex supplements.

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Issues with Cheap B-Complex Supplements

The biggest issue I see with the general population taking a standard B-complex from the grocery store is that most B-complexes don’t contain the best forms of the nutrients that they provide.

Some forms are just less effective. Others are downright dangerous when taken in excess.

Here are some of the most common cheap B-vitamins to avoid, and their higher-quality alternatives.

Folate vs Folic Acid

The best example of this issue is with the B-vitamin folate. Folate is a crucial nutrient for good health in all stages of life, and especially while you’re pregnant or planning to become pregnant.

The primary supplemental form used in both B-Complexes and fortified foods is folic acid. And the problem with folic acid is that it’s synthetic, so it’s not processed by the body in the same way as natural folate.

Research shows that there are many benefits to using the natural form of folate (5-methyltetrahydrofolate, or 5-MTHF).

This version of folate is preferable to folic acid because it is better absorbed, does not mask B12 deficiency as easily, and helps avoid the pitfalls of unmetabolized folic acid in circulation. All of which can lead to an increased risk of cancer.

For more about the folate versus folic acid issue, check out Chris Kresser’s comprehensive post on the topic.

Cyanocobalamin vs Methylcobalamin (Vitamin B12)

Vitamin B12 has a few different forms that vary in efficacy and safety.

Cyanocobalamin is the most commonly used (read: less expensive) form of the nutrient, and yet this form is not found in nature.

Rather, the B12 form that is most desirable is methylcobalamin (or adenosyl/hydroxy cobalamin for some folks), which is the form found in food.

This is not only because of this version’s function as a methyl donor but also because of concerns that the metabolism of cyanocobalamin may release small amounts of cyanide into the system.

This would never be enough to cause cyanide poisoning. It’s a potential issue for people who have impaired detox due to genetic issues, nutrient deficiencies, or chronic illness.

And Dr. Chris Masterjohn believes cyanocobalamin may not be effective. This is because we need B12 to excrete cyanide from our bodies (discussed at the 18:01 mark).

There may be other quality issues with the typical B-Complex vitamins you’ll find in the grocery store (such as B6 variations). But these are the two primary ones I see and are the primary nutrients I consider when assessing the quality of any B-Complex my clients are taking.

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Not All B-Vitamins are Represented

One would think that a B-Complex should provide adequate levels of all the important B-vitamins, right? Unfortunately, there are some nutrients often completely absent from the typical B-vitamin supplement.


Choline is the primary nutrient that I see getting left out of most major B-Complexes. This may be because we’ve only recognized choline as a vitamin (i.e. essential) since 1998.

But isn’t two decades long enough to get with the program? I don’t quite understand why choline isn’t a regular feature in most B-Complexes. And if it is included at all, it’s usually in a woefully inadequate amount.

You can get choline from egg yolks and a variety of vegetables. But there are some people who may have higher needs or that cannot eat egg yolks due to intolerance or autoimmune issues.

Plus, choline may be as important as folate and B12 for promoting a well functioning methylation cycle. Plus it can actually protect against deficiency symptoms of the other B-vitamins. So any B-Complex worth taking should contain at least 200 mg of choline, in my opinion!


Biotin is another nutrient that is frequently underrepresented in B-Complexes. Some don’t contain it at all, while others only provide around 1/3-1/2 of the daily value.

Biotin is a great supplement for skin, hair, and nail health, and may also help improve blood sugar control. So look for a B-complex that provides 100% of your daily needs of biotin.

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Look for Supplements with Appropriate Quantities of Each Vitamin

The amounts of the individual vitamins contained in each supplement dose vary as well. And you want to be careful about how much of any specific nutrient you’re getting, especially if you’ll be taking the vitamin daily.

Vitamin B12 has no established upper limit, meaning there’s no toxicity seen even at high doses. But other vitamins like folate and B6 can potentially be toxic or cause poor long term health outcomes if taken in excess for a long period of time.

For most people, I don’t suggest taking over 800 mcg of folate and 100 mg of B6 on a daily basis (but those with MTHFR are a different story).

You should read the label carefully of any B-Complex you’re buying. Some supplements (this one for example) don’t even contain B12 or folate, which I’d think are two of the B-vitamins you’d expect to see in a B-Complex.

So as with any supplement, ALWAYS read the label to see exactly what you’re getting, and do the research ahead of time before you go to the store.


My B-Complex Recommendations

Assuming you don’t have a methylation genetic defect, I like Integrative Therapeutics Active B-Complex as a well-rounded, high-quality B-vitamin supplement.

It has the active forms of B12 and folate, as well as a good amount of a highly bioavailable form of B6. This supplement contains 250 mg of choline, 100% of the daily value for biotin, and a significant amount of all the other important B-vitamins.

You can also take it in a half-dose if there are concerns about over-supplementation, as each dose is 2 pills (i.e. take 1 pill for a half dose).

Integrative Therapeutics is also a fantastic brand with a hypoallergenic formulation, making it appropriate for people with food sensitivities. And there’s no magnesium stearate in it, which some people report issues with.

Remember, those with the MTHFR SNP need to avoid folic acid and supplement with 5-Methyltetrahydrofolate (5-MTHF), while those with COMT should limit 5-MTHF and use adenosyl/hydroxycobalamin as a B12 supplement.

I hope you have a better understanding of the thought process that goes into choosing a B-vitamin complex, and now know how to confidently choose the right vitamin that works for you and your specific health needs!

Did this article change your perspective on B-Complex supplementation? Are you planning to change the B-vitamins you use? Let me know in the comments below!

CLICK HERE to order high-quality supplements, including the B-vitamins I mentioned above!

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I'm a women's health expert and a registered dietitian (RD) with a passion for helping goal-oriented people fuel their purpose.

I help nutrition entrepreneurs grow their income and their impact by packaging their brilliance into transformative coaching and consulting programs, and get crystal clear on their marketing strategy.

I'm on a mission to help nutrition business owners drop the hustle and come into alignment with their ideal business goals, so they can work from a sense of ease and abundance, and build the online business of their dreams. 

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