Medically reviewed on May 17, 2022 by Jordan Stachel, M.S., RDN, CPT. To give you technically accurate, evidence-based information, content published on the Everlywell blog is reviewed by credentialed professionals with expertise in medical and bioscience fields.
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If you’ve ever looked at the back of a cereal box or multivitamin pack, you’ve seen all the vitamin letters—A, C, E, K, and so on. While you’ll notice that every other letter appears once, vitamin B shows up several times. So why are there multiple B vitamins? And what is the difference specifically between vitamin B6 and B12?
In short, both B6 and B12 participate in red blood cell production and help boost immunity. More specifically, they support healthy immune system function, as immunity is an immune response against a specific antigen. However, they also take on separate functions. Vitamin B6 works to regulate hormones, while B12 is essential to nerve function and DNA synthesis .
To explore this distinction in-depth, we’ll look at both vitamins and shed light on their functions, the recommended daily intake, signs of deficiencies, and more.
All B vitamins—eight of them in total—are part of a larger group of vitamins known as the “B complex.” Let’s separate two of them from the pack and place them under the microscope.
Also called “pyridoxine,” vitamin B6 is a water-soluble vitamin that exists naturally in many foods. Like all vitamins, B6 is an organic compound that humans need to sustain life.
More specifically, the term “vitamin B6” refers to six separate compounds called “vitamers.” These are :
All of these compounds work together to fulfill the roles of B6 vitamins.
Cobalamin (better known as vitamin B12) is also an organic compound and a water-soluble vitamin. The name “cobalamin” comes from the presence of cobalt in vitamin B12.
On its way into our systems, B12 binds to proteins in food. As it travels through the digestive system, it slowly separates from the protein and stores itself in the body for future use .
So, from a classification standpoint, vitamin B6 and vitamin B12 are practically the same. The real differences start to show when you examine their functions within the body.
Curious what vitamin B6 is good for? Since the body needs vitamin B6 for more than 100 metabolic processes, dietitians consider it an essential nutrient. Essentially, the human body cannot synthesize B6, thus we have to eat it.
Along with its role in metabolism and the production of red blood cells, vitamin B6 can :
In other words, vitamin B6 is essential to health and well-being.
B12 is equally important; many internal processes depend on this compound for regular function. While red blood cell production is one of the most well-known functions that B12 takes part in, the vitamin can also [4, 5]:
Overall, it’s crucial to consume enough vitamin B12.
As with all nutrients, it’s possible to take in too little—or too much. Although vitamin B6 and B12 are part of the same vitamin family, the amount needed for each one varies considerably.
How much B6 should you have? According to the National Institutes of Health (NIH), the recommended dietary allowance (RDA) for vitamin B12 varies according to age, sex, and whether one is pregnant . Their official guidelines for daily intake are as follows:
Additionally, the NIH recommends 1.9 mg per day if you’re pregnant and 2.0 mg per day if you’re lactating—no matter your age.
You can take in more vitamin B6 by consuming foods high in B6, such as :
Some individuals—especially vegetarians and vegans— may struggle to consume enough vitamin B6. In these cases, vitamin supplements are an excellent way to meet daily dietary needs.
Unlike B6, the RDA for vitamin B12 is in micrograms (mcg)—that is, one one-thousandth of a milligram.
The NIH recommends that all individuals 14 years and older consume 2.4 mcg of vitamin B12 per day . Pregnant people of any age require 2.6 mcg every day, while those lactating should take in 2.8 mcg per day.
Vitamin B12 is present in many animal food products; excellent sources include:
Vegans and vegetarians can find a small amount of vitamin B12 in tempeh, fortified breakfast cereals, and nutritional yeast . As with B6, dietary supplements can help you reach the RDA for B12—especially if you don’t eat meat or dairy.
As mentioned, our bodies depend on B vitamins for various processes. When these internal mechanisms go awry due to a lack of vitamins, the body finds ways to tell you.
Depending on the severity of a vitamin B6 deficiency, you may experience symptoms like :
According to a recent study in the journal Nutrients, there is also growing evidence that a lack of vitamin B6 can increase the chances of developing some forms of cancer .
Thankfully, some of these signs and symptoms are easy enough to spot. However, even if you don’t experience physical symptoms, you may still have a vitamin B6 deficiency.
While it’s extremely rare to consume too much vitamin B6, it can happen. However, it would be nearly impossible to intake too much of the vitamin through diet alone. Realistically, the only way to take in a harmful dose of vitamin B6 is by taking high-dosage dietary supplements for a prolonged period .
As per the NIH, the upper limit for daily consumption in adults aged 18 and over is 100 mg . That’s around 60 times the recommended daily amount. (For reference, a full cup of chickpeas contains 1.1 mg—imagine eating 100 cups of chickpeas.)
Overconsumption of B6 could eventually lead to:
Even if you’re taking vitamin B6 supplements, don’t panic. We want to stress that it’s incredibly difficult to take too much B6. Plus, symptoms usually resolve themselves when you stop taking supplements.
The likelihood of a vitamin B12 deficiency increases with age . Vegans and vegetarians could be even more prone to a deficiency, as most of the significant sources of vitamin B12 come from animal food products.
Signs of low B12 levels can include :
According to the National Institutes of Health, there is no risk in taking more than the recommended amount of vitamin B12 .
Are you still wondering about the differences between vitamin B6 and vitamin B12? Let’s look at the facts from a more practical standpoint and clear up any lingering questions.
Absolutely—even though B6 and B12 are both members of the B-vitamin complex, they fulfill different roles within the body.
Because you need both vitamins, you may feel the need to increase the variety of foods consumed. Fortunately, many foods that contain vitamin B6 also contain B12, including:
Neither vitamin is better than the other—they’re both equally essential to your well-being. To maintain a healthy lifestyle, you need to consume the correct amount of all vitamins and micronutrients.
You should only favor one vitamin over the other if you have a deficiency in one but not the other and a healthcare provider advises you to do so. In these cases, you may receive a prescription for the individual B vitamin rather than the entire B complex.
You can—in fact, in many cases, it’s unavoidable (in a positive sense). Foods like meat, fish, and fortified cereals usually contain vitamins B6 and B12.
1. Kennedy DO. B Vitamins and the Brain: Mechanisms, Dose and Efficacy--A Review. Nutrients. 2016;8(2):68. Published 2016 Jan 27.
2. Vitamin B12: Fact Sheet for Health Professionals. National Institutes of Health. URL. Accessed May 17, 2022.
3. Vitamin B6: Fact Sheet for Consumers. National Institutes of Health. URL. Accessed May 17, 2022.
4. Peterson CT, Rodionov DA, Osterman AL, Peterson SN. B Vitamins and Their Role in Immune Regulation and Cancer. Nutrients. 2020;12(11):3380. Published 2020 Nov 4.
5. Pawlak R. Is vitamin B12 deficiency a risk factor for cardiovascular disease in vegetarians? Am J Prev Med. 2015 Jun;48(6):e11-26.
6. Vitamin B6 Deficiency. StatPearls [Internet]. URL. Accessed May 17, 2022.
7. Vitamin B12 Deficiency. StatPearls [Internet]. URL. Accessed May 17, 2022.
8. Vitamin B-12 Deficiency Anemia. Cedars Sinai. URL. Accessed May 17, 2022.