In 1912, a Polish chemist named Casimir Funk discovered a substance vital to human health that the body cannot produce on its own. He called it a “vitamine,” a portmanteau of “vital” and “amine” (due to a mistaken belief that this substance was an amino acid). Things got slightly more complicated when another such substance was found, but the scientists handled it with aplomb: They called one “vitamin A” and the other — do you see where this is going? — “vitamin B.” Then came C, and D, followed by E, and then K, as several compounds in a row (F, G, H, I, and J, presumably), didn’t pass vitamin muster.
But then things started getting messy. When researchers began to realize that vitamin B was actually an entire family of substances, similar in form and function, but unique in the roles they play in human health. Instead of adding more letters (there weren’t that many left, and who knew where this proliferation of Bs was going to end), the namers turned to numbers: B1, B2, B3, B5, and so on.
A few things here. First, there’s no B4, which you could charitably chalk up to not wanting to be responsible for the following hypothetical conversation:
Parent: “Did you take your B4?”
Child: “Did I take my what before?”
Thank you, science.
Second, while there are eight B vitamins, there are no B batteries, which feels suspicious to me.
And third, the Bs aren’t even named in chronological order. If you peruse the 1,098-page classic, Handbook of Biochemistry and Molecular Biology, Fourth Edition, by Lundblad and McDonald, you’ll learn that B12 was first identified in 1926, while B3 wasn’t discovered until 1936. Either these folks had other things on their minds, or time travel is real. You decide.
Anyway, none of that is to take away from the importance of the B family of vitamins. In fact, all of them are essential for a healthy body and mind, and play an integral role in how your body functions, starting at a cellular level.
Conventional nutritional wisdom holds that the best places to find B vitamins are in animal products, where you can generally find them in abundance. But is it possible to get what you need from plant-based foods? What are the health benefits and risks of the various B vitamins? And should you supplement? These are the questions that we’ll tackle in this article. And we won’t take 1,098 pages to do it.
What Are the B Vitamins?
B vitamins refer to a group of eight different vitamins that make up what’s often called the B-complex. The B vitamins are:
- Thiamin (vitamin B1)
- Riboflavin (vitamin B2)
- Niacin (vitamin B3)
- Pantothenic acid (vitamin B5)
- Pyridoxine (vitamin B6)
- Biotin (vitamin B7)
- Folate (vitamin B9)
- Cobalamin (vitamin B12)
This group of vitamins helps your body convert food into energy — a process known as metabolism — as well as create new blood cells. They’re also important for the maintenance of healthy skin cells, brain cells, and other body tissues.
Like vitamin C, the B vitamins are water-soluble. Unlike the fat-soluble vitamins A, D, E, and K, which are best absorbed when ingested alongside dietary fats, the water-soluble vitamins can be taken with water and then used by your body. Bacteria in the intestinal tract of animals produce B vitamins, which is why some nutritionists have recommended eating animals to meet your daily requirement. This isn’t necessary, as many plants also contain these nutrients (see below for examples).
In fact, scientists recently discovered that bacteria in the human microbiome also generate B vitamins. This makes logical sense, given that humans are, in fact, animals, but there are a couple of reasons that we can’t rely exclusively on our internal B factories.
First, not every human digestive tract produces enough of these compounds. Second, you absorb B vitamins in the small intestines, but the bacteria that manufacture these vitamins are located in your large intestines. Since the large intestines are the next to last stop on the poop train, it’s not clear how fully and efficiently those vitamins get to their absorption sites.
For these reasons, many of us need to be intentional with our dietary sources of B vitamins to make sure we’re getting enough. Given that there are eight of them, that might seem like a full-time job. But luckily, most B vitamins are found together in many foods, making this task much simpler than keeping track of each one separately.
8 Key Benefits of the B Vitamins
1. Protect Against Diabetes
Getting enough B vitamins is important for regulating your blood sugar. Lower levels of B1, B6, and B7 have been observed in people with diabetes, and supplementing these has been shown to improve metabolic control. Additionally, pharmaceutical doses of B1 and B3 may be useful to prevent kidney and cardiovascular complications in people with type 2 diabetes. The absorption of B9 and B12 has been found to decrease with metformin use, a drug commonly used to manage blood sugar in type 2 diabetes. So if you have type 2 diabetes or other conditions that require close monitoring of your blood glucose, it’s extra important to make sure you’re getting enough of those two B vitamins.
2. Protect Against Heart Disease
Vitamins B6, B9, and B12 help reduce levels of the amino acid homocysteine, which contributes to increased cardiovascular disease risk when elevated (called hyperhomocysteinemia, and worth 8 gazillion points in Scrabble). These B vitamins improve vascular endothelial function and help keep your blood vessels dilated, which supports healthy circulation and is good for your heart.
Vitamins B3 and B5 have traditionally been associated with improving cholesterol — B3, aka niacin, in particular, was once widely used as a cholesterol-lowering drug and has been called “the granddaddy of cholesterol-lowering drugs” by Harvard Medical School.
The picture has grown more complicated since niacin’s cholesterol-fighting heyday in the 1950s. Research has consistently shown that high-dose niacin supplementation does not meaningfully reduce cardiovascular events when added to statin therapy. In fact, too much niacin can actually be dangerous. A 2024 study published in Nature Medicine found that excess niacin produces a metabolite called 4PY that may actually promote vascular inflammation and increase the risk of heart attack and stroke.
As a result, high-dose niacin is no longer recommended as a standard treatment for high cholesterol. There’s still plenty of positive news about niacin from whole food sources, though. Getting your B3 from foods like brown rice, nuts, seeds, legumes, and bananas is still good for you and doesn’t carry these risks.
3. Protect the Brain and Prevent or Treat Alzheimer’s Disease
Vitamins B2, B6, B9, and B12 play a role in cognitive health, and a 2025 systematic review of 17 clinical trials found that supplementing with them offered a modest benefit on global cognitive function in older adults.
Some observational studies have found an association between low serum folate (B9) levels, worse cognitive function, and a higher risk for Alzheimer’s. And low serum B12 is also associated with poor brain function. Vitamin B1 is a key factor in protecting against alcohol-related dementia, as it can prevent the accumulation of iron deposits in the brain that lead to deterioration. B1 may also have the potential to help people with mild Alzheimer’s, according to a recent small exploratory clinical trial published in the Journal of Alzheimer’s Disease.
All that said, while the associations between B vitamins and brain health are real, it’s not clear yet whether B vitamin supplementation can meaningfully prevent or slow cognitive decline.
4. Protect Against Cancer
Getting your B vitamins may boost your protection against certain cancers. Vitamins B2, B6, and B9 have been shown to work against cancerous tumors when applied to lymphoma cells in a lab setting. Vitamin B6 has also been shown to reduce the risk of lung cancer. In one study, researchers followed almost 160,000 women for 18 years and found that women who took at least 50 milligrams per day of supplemental vitamin B6 had a 16% reduction in lung cancer risk compared to those who did not take the vitamin.
And while a 2017 study appeared to suggest that vitamin B12 supplementation might increase lung cancer risk among men, especially if they smoked, data from many randomized controlled trials have found that there’s no reason to believe B12 supplementation has any adverse effect on cancer risk. In fact, a small study among 400 Canadian women found that supplemental B9 and B12 could reduce the risk for breast cancer, particularly among those with BRCA1 gene mutations.
5. Improve Mood
All B vitamins — and especially B6, B9, and B12 — seem to help prevent depression, stress, and anxiety. A 2019 meta-analysis and review of 16 studies concluded that, compared with a placebo, B vitamin supplements appear to help improve overall mood and reduce stress, especially among people at higher risk of poor nutrition or with poor mood. (For people who prefer plain talk, I think “poor mood status” can be translated to “feeling crappy.”)
6. Protect Against Birth Defects
The B vitamins are also crucial for supporting a healthy pregnancy and normal fetal development. Getting enough B9 and B12 is important to the development of a baby’s spinal cord. This is why it’s standard practice to educate mothers-to-be on supplementing with folic acid and eating folate (B9)-rich foods like dark leafy greens, lentils, and oranges during pregnancy, to meet their minimum 400 micrograms per day requirement of this nutrient. In addition, some research suggests that vitamin B3 may help bypass genetic mutations that can cause certain birth defects or an increased risk of miscarriage.
7. Balance Hormones
B vitamins have many roles within the reproductive system and may help naturally maintain hormonal balance. Many women find success with supplemental vitamin B6 for alleviating nausea associated with morning sickness, as well as reducing symptoms of premenstrual syndrome. And vitamins B3 and B5 are needed for hormone production in the adrenal glands, including sex and stress hormones.
8. Keep Nails, Hair, and Skin Healthy
All of the B vitamins may work together to keep your hair, skin, and nails healthy, but B7, B9, and B12 may be especially helpful. Biotin (B7) deficiency often presents as brittle nails, hair loss, and skin rash, and while evidence is mostly anecdotal, biotin supplementation is often used in hopes of improving these conditions. Changes in your nails are often the result of micronutrient deficiencies, including an array of B vitamins. In fact, a B12 deficiency may show up as entirely blue nails or other dark pigmentation. And a folate (B9) deficiency can cause your nails to become brittle and rigid.
For more information about how to eat for healthy nails and hair, here’s our full article.
And for an article about the best foods for healthy skin, we’ve got you covered as well.
Sources of B Vitamins
Now that you know how important B vitamins are to your health, where can you find them? Fortunately, there are many sources of B vitamins in whole foods that you may already enjoy — or can easily add to your diet.
B Vitamin Food Sources
Most B vitamins can be found in animal products, like meat, fish, eggs, and dairy, but some of the best sources are plant-based and include whole grains, legumes, seeds, nuts, leafy greens, fortified foods, bananas, mushrooms, avocado, potatoes, sweet potatoes, and broccoli.
More specifically, below are some of the best places to find each of the eight B-complex vitamins from plant-based foods:
- Vitamin B1: beans, peas, lentils, and sunflower seeds
- Vitamin B2: almonds, tofu, mushrooms, avocado, and spinach
- Vitamin B3: brown rice, nuts, seeds, legumes, and bananas
- Vitamin B5: mushrooms, avocado, nuts, seeds, potatoes, brown rice, oats, and broccoli
- Vitamin B6: chickpeas, dark leafy greens, papayas, bananas, oranges, and cantaloupe
- Vitamin B7: sweet potatoes, nuts, seeds, and avocado
- Vitamin B9: dark leafy greens, beans, peanuts, sunflower seeds, and oranges.
- Vitamin B12: fortified nutritional yeast and breakfast cereals, as well as enriched plant-based milks and yogurts
B Vitamin Supplements
Most of the B vitamins (other than B12) can be obtained from eating a variety of whole foods. But you may want to supplement with certain ones if you don’t think you get enough from your diet, or if you fall into a group at higher risk of deficiencies.
You may want to consider supplementing with folic acid — the more bioavailable synthetic form of folate — if you fall into a group that’s at higher risk for folate deficiency, like pregnant women and people with a history of chronic alcohol use.
Vitamin B12 also deserves extra attention because it’s not readily found in plant foods. Still, it’s not just plant-based eaters who are at risk. In fact, one study conducted in 2000 by researchers at Tufts University found that nearly 40% of Americans (including omnivores) might have been deficient in this B vitamin. As such, supplementation may be advisable for most people and is strongly recommended for vegans. For more on B12, see our article here.)
If you choose to supplement, you’ll most often find all the B vitamins combined as a B-complex. Alternatively, you can take individual B vitamin supplements, but this isn’t usually necessary. The exceptions are if you know you’re deficient in certain ones or want to maximize a specific B vitamin and not the others.
It’s also worth noting that if you choose to take a daily multivitamin with minerals, it likely contains all the B vitamins.
Risks of Taking B Vitamin Supplements
Risks of potentially overdosing on B vitamins are usually associated with taking too many B vitamin supplements, not with eating too many foods rich in them. And in general, risks associated with taking B vitamin supplements are rare because of their water-soluble nature. If you consume too much, your body will eliminate the excess through urine. Despite this built-in “overflow mechanism,” an overdose of B-complex is possible and may result in symptoms like excessive thirst, skin rashes or flushing, blurred vision, abdominal cramps, nausea, vomiting, increased urination, and diarrhea.
It’s also worth addressing niacin (vitamin B3) specifically, since it was historically prescribed at high pharmacological doses to lower LDL cholesterol and raise HDL cholesterol. At those levels, a common side effect is the “niacin flush” — a reddening of the skin, often around the face and neck, typically appearing within 30 minutes of ingestion.
While the flush itself is not dangerous, high-dose niacin carries more serious concerns. As we’ve seen, excess niacin may increase cardiovascular risk. For this reason, high-dose niacin supplementation should only be pursued under the direct supervision of a healthcare provider, and for most people with high cholesterol, other evidence-based options are now preferred. Again, there’s no need to worry about overdosing on niacin from brown rice or lentils; food-sourced B3 doesn’t carry these risks. As a side note, many internet sites recommend the niacin flush as a strategy to pass a drug test if you’d otherwise test positive for THC (the active ingredient in marijuana). Let me save you some time: It doesn’t work. (I say this as a student of research, and not from personal experience.)
One more oddity: People who take supplemental B2 (riboflavin) may find that they develop abnormally bright or neon yellow urine. If this happens to you, don’t worry. You aren’t necessarily dehydrated, and you certainly aren’t in danger of turning yellow. Your body is just excreting some of the riboflavin that it doesn’t need. Just pretend you’re a human highlighter or superhero from the planet Neon.
Testing for Deficiency
If you’re experiencing symptoms that might signal a B vitamin deficiency — like unusual fatigue, a skin rash, numbness or tingling in the hands or feet, tongue inflammation, or signs of anemia — it’s worth talking to your healthcare provider. A simple blood test can check your levels of specific B vitamins, and a 24-hour urine test is sometimes used as well. These tests can confirm whether a deficiency exists, though they can’t always tell you whether the cause is dietary or related to absorption problems. Either way, they give your healthcare provider a starting point for figuring out the right approach.
Some people are at higher risk for B vitamin deficiencies and may want to discuss testing proactively, even without obvious symptoms. This includes people with a history of heavy alcohol use, malabsorption conditions like Crohn’s disease or celiac disease, those who have had bariatric surgery, older adults, and people eating a fully plant-based diet, particularly regarding B12.
It’s also worth knowing that doctors sometimes skip formal testing when symptoms and context make a deficiency highly likely and simply recommend supplementation to see if things improve. If they do, that’s useful information in itself.
Vitamin B-Strong Recipes
With the exception of B12, getting plenty of B vitamins on a plant-based diet can be easy when you add a variety of whole, healing plant-based foods to your plate. Mushrooms may not shout “we’re good for you” as loudly as kale, but they sure do pack a lot of nutrition, including several B vitamins. Add fortified nutritional yeast and whole grain breadcrumbs to Super Stuffed Mushrooms, and you get a B vitamin smorgasbord!
Sweet and Savory African Soup — is it soup or breakfast? The truth of the matter is that we like to enjoy this B-vitamin-rich soup for dinner, then devour the tasty leftovers for breakfast (because it gets even better overnight!). So, it’s your choice; enjoy it for soup, breakfast, or any time of the day.
Finally, B vitamins never tasted as good as they do in the Chunky Monkey Smoothie. Chocolate and vitamins? Who knew!
1. Super Stuffed Mushrooms
Starting with the superstar mushroom, you get a rich source of B vitamins like riboflavin, niacin, and pantothenic acid. Add nutritional yeast for B12 (if it’s fortified). Then get even more B vitamins by using whole grain bread for breadcrumbs, which provide folate and thiamine. This appetizer is not only tasty but it’s also a B-vitamin jamboree!
2. Sweet and Savory African Soup
What’s in this soup that doesn’t contain an abundance of B vitamins? Not much! Peanut butter, chickpeas, sweet potatoes, and spinach all provide a variety of B vitamins to support brain health, heart health, cancer prevention, and mood. Plus, it is pretty delicious!
3. Chunky Monkey Smoothie
Vitamins never tasted so good! Getting your daily dose of B vitamins in a healthy, indulgent smoothie might be the most fun and delicious way to support brain, heart, and skin health. You’d never know that leafy greens snuck their way into this creamy chocolate-y blend!
B Vitamins Can Be Easy
B vitamins are important to just about every system in your body. And they’re protective against common and potentially lethal chronic diseases, as well as important for a healthy pregnancy, for hormone production, and for your hair, skin, and nails. While all the B vitamins can be found in whole foods, a few people may struggle to get enough of them. However, avoiding deficiency is relatively easy with testing when indicated and, in some cases, by adding appropriate supplements. Hopefully, this article has helped you to B proactive with your wellbeing!
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Tell us in the comments:
- Do you take B-complex or any individual B vitamin supplements?
- Have you ever experienced a deficiency in any of the B vitamins? What did that look like for you?
- Where do you find B vitamins in your diet?
Feature image: iStock.com/OksanaKiian
Read Next:
- Vitamin B12: Why it’s Important and How to Avoid B12 Deficiency
- Folate (B9): What It Is, Where to Get it, and Why Folate is Different from Folic Acid
- How to Get Maximal Nutrition from Your Food: Putting Food Combining, Sourcing, & Preparation Methods to Work for You
