Best B12 Supplement (2024): Highly Bioavailable Forms With Limited Fillers

Vitamin deficiencies can be hard to diagnose, but a 2015 report in Clinical Medicine¹ estimated the prevalence of vitamin B12 deficiency in the U.S. at 3% to 6%, depending on your age. Even without a true deficiency, it’s possible that your B12 levels aren’t as high as they should be—a condition called marginal depletion that affects 15% to 20% of adults (and is more common in older adults). 

Vitamin B12, officially called cobalamin, is crucial to forming healthy red blood cells and maintaining your energy levels. Without enough in your system, you may find yourself dragging throughout the day. And because vitamin B12 deficiency can contribute to anemia, and have lasting negative effects on your nervous system, it’s important to make sure you’re meeting your needs daily. 

Vitamin B12 is also a water-soluble vitamin, so it doesn’t stay stored in your body like fat-soluble vitamins can—that’s why it’s tagged as an essential nutrient (meaning you need to take it every day).

While it’s always ideal to get your vitamins from food sources, vitamin supplements can help bridge the gap between what you’re getting and what you need to maintain optimal health. The problem is that dietary supplements aren’t closely regulated, so there’s a lot of junk out there. To help you sort through the noise, we chatted with Ashley Kitchens, MPH, RDN, plant-based registered dietitian and owner of Plant Centered Nutrition, and registered dietitian Bob Iafelice, Ph.D., to get their expert takes. We used their general advice and our own experience trying these supplements to come up with this list of the best vitamin B12 supplements.

Medical disclaimer: This article is intended for educational and informational purposes only. It is not intended as a substitute for medical advice. For health advice, contact a licensed healthcare provider. GGR also recommends choosing a product that has been third-party tested for quality.

Advice Backed By Experts

As certified personal trainers and nutrition coaches, our testers know a decent amount about supplements. But for this guide, we also enlisted the help of a registered dietitian and a functional nutritionist to make sure we were making the best recommendations for you.

Best B12 Supplements

• Best B12 Supplement Overall: ProHealth Vitamin B12
• Best Multivitamin with B12 for Women: Transparent Labs Multivitamin
• Best Multivitamin with B12 for Men: Onnit Total Human
• Best Budget B12 Supplement: Nutricost Vitamin B12
• Best Liquid B12 Supplement: Cymbiotika Liposomal B6 + B12 Liquid
• Best B-Complex Supplement: Double Wood Vitamin B Complex
• Best Vegan B12 Supplement: HUM Nutrition B12 Turbo
• Best B12 Gummies: Olly Daily Energy Gummies
• Best High-Dose B12 Supplement: Bulletproof Methyl B12 5,000 mcg Lozenges

Best B12 Supplement Overall: ProHealth Vitamin B12

Good for: Those looking for an easy-to-take B12 with third-party testing and multiple forms of B12

Best B12 Overall

ProHealth Vitamin B12

GGR Score: 4.4

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Product Highlights

• Contains 4 forms of Vitamin B12: methylcobalamin, dibencozide, hydroxocobalamin, and cyanocobalamin
• 75-day money-back guarantee
• Available in 30 and 120 servings
• Flavored, dissolvable lozenge
• Third-party tested

Pros & Cons

Pros

• Contains 4 forms of B12
• Budget-friendly
• Third-party tested
• 75-day money-back guarantee

Cons

• Only available in 1 flavor
• Must order 120 serving size to get free shipping
• May take lozenge awhile to dissolve

Bottom Line

ProHealth Vitamin B12 contains four forms of B12 in one dissolvable strawberry lozenge. It's also third-party tested and budget-friendly with a 75-day money-back guarantee.

We chose ProHealth Vitamin B12 as the best B12 supplement overall with a score of 4.4 out of 5 because it covers all the bases. While most B12 supplements have one form of B12, this one contains four: methylcobalamin, dibencozide, hydroxocobalamin, and cyanocobalamin. All of them are high-quality and highly absorbable, and according to supplement expert Dr. Bob Iafelice, MS, RDN, LDN, hydroxycobalamin stays in your body longer and is converted to the active, methyl form of vitamin B12 when your body needs it. In other words, it sticks around so your body can use it when it needs a readily available source of B12.

In addition to the variety of B12 types, the ProHealth Vitamin B12 also has a high enough dosage (5,000 mcg) to bypass the need for intrinsic factor—a protein made by your stomach that helps absorb vitamin B12²—when necessary, according to Iafelice. Some people, like those with pernicious anemia, don’t make enough intrinsic factor, so this supplement can provide enough of the active form of the vitamin to help those people get what they need anyway.

It’s a lozenge, so it’s easy to take, and it’s sugar-free and doesn’t contain any artificial sweeteners—a rarity for gummies or lozenges. That said, GGR Director of Fitness Content Kate Meier, USAW-L1, CF-L1, CPT, did run into some issues with the taste and solubility, saying, “I had this thing under my tongue for 30 seconds, and it was NOT dissolving! I ended up chewing it. I do like pills I can chew, but if this is supposed to be dissolvable, it doesn’t do a great job of this. So, for that reason, it’s a 3.5 out of 5.”

ProHealth opts into third-party testing and makes certificates of analysis (COAs) available on their site so you can double-check the label and verify that you’re getting what they say you are. 

Overall, Iafelice calls this “a top-tier B12” and highly recommends it.

Best Multivitamin with B12 For Women: Transparent Labs Multivitamin

Good for: Women (or anyone) looking for a multivitamin with a highly-absorbable form of B12 

Best B12 For Women

Transparent Labs Multivitamin

GGR Score: 4

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Product Highlights

• Ultra-potent multivitamin designed for active adults 
• No artificial sweeteners, coloring, or preservatives
• Available through a  subscription or 1 time purchase

Pros & Cons

Pros

• Subscribe and save
• More than 20 ingredients
• Reported to be easy on the stomach

Cons

• May be sold out
• Only available from company website
• Limited customers reviews
• Large serving size that requires you to take 4 pills

Bottom Line

Transparent Labs Multivitamin is designed to support overall wellness for active adults. This supplement has limited but very positive reviews and may be sold out when you go to buy it.

Unless you’re sure that you’re deficient in vitamin B12 specifically, you may want to opt for a multivitamin, which provides all the essential vitamins and minerals you need to stay healthy. 

The Transparent Labs Multivitamin is our top pick for this category because it combines 200 mcg of highly absorbable vitamin B12 (methylcobalamin) with almost all of the other major vitamins and minerals you need daily. The only mineral missing is iron, which is better to take separately anyway if you’re of reproductive age and need more of it.

In addition to vitamins and minerals, this supplement also contains ashwagandha, which can help your body adapt to stress.

On a more general note, we love Transparent Labs products because the company doesn’t use questionable or low-quality ingredients, and they third-party test everything. All COAs are also easily available on their website, which really plays into the “transparency” in Transparent Labs—they don’t try to hide anything.

The only downside to this supplement compared to others is that you have to take four capsules for a single serving; with others, you only need one. That said, this gives you some leeway to adjust your dose if you only want to take half.

Best Multivitamin with B12 For Men: Onnit Total Human

Good for: Those looking for a comprehensive supplement pack who are OK with taking a lot of capsules daily

Best B12 For Men

Onnit Total Human

GGR Score: 4

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Product Highlights

• Complete supplement packs 
• Day and night packs of supplements 
• All-in-one product

Pros & Cons

Pros

• Subscribe and save
• Combination of Onnit’s best products
• Day pack for energy and night pack for better sleep
• High dosages of vitamins and minerals

Cons

• Customers complain of receiving only partial doses of multiple supplements
• Relatively expensive
• More than 15 pills per day

Bottom Line

Onnit Total Human is an expensive supplement pack with a lot of pills, designed for people that want everything they need in one place and want to use a variety of Onnit’s products.

Men have unique nutrient needs—they typically don’t need as much iron or folic acid as women. Because of this, the Onnit Total Human is made without iron and lower doses of folate, plus 187 mcg of vitamin B12, well over the 2.4 mcg recommended for men to take daily. The vitamin B12 in the formula is in the superior form of methylcobalamin, and it’s coupled with a boatload of different nutrients, like other B vitamins and minerals, as well as a “Performance Blend,” that includes adaptogens like ashwagandha and green tea extract.

In addition to supporting your vitamin B12 needs, this supplement pack is designed to help with energy, focus, and calm. This isn’t a single capsule—it’s a blend of supplements that work synergistically to provide the most benefits. One thing to note: You have to take a LOT of pills to get the full dosages. There are two packs—one you take in the morning and one at night. 

Each pack has eight pills, so you’ll be taking a total of 16 pills per day. Jacob Penner, USAW-L2, CF-L1, the certified personal trainer who tested Onnit Total Human, says he can swallow the entire pack in one gulp, but others may want to break it up. As for side effects? Jacob says he experienced some vivid dreams, but other than that, his experience was positive.

Another nod to the brand, Onnit does third-party testing, and many of its products are Informed-Sport Certified, meaning they don’t contain any banned substances that would disqualify competitive athletes.

Best Budget B12 Supplement: Nutricost Vitamin B12

Good for: Anyone who wants a quality supplement at a lower price

Best Budget B12

Nutricost Vitamin B12

GGR Score: 4.8

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Product Highlights

• $0.08/serving
• 120 servings per container
• 1,000 mcg B12 (Methylcobalamin)
• Third-party tested
• 60-day money-back guarantee

Pros & Cons

Pros

• 1,000 mcg B12 (Methylcobalamin)
• Budget-friendly
• Third-party tested
• 1 daily capsule

Cons

• Only contains one form of B12

Bottom Line

Nutricost B12 features 1,000 mcg of Methylcobalamin B12 in one easy-to-swallow capsule.

You have to be careful when buying budget supplements because there are a lot of inferior products out there. We like the Nutricost line because the supplements are an incredible value—you can get three months’ worth for just about $12—but they don’t cut any corners. 

This vitamin B12 supplement comes in three strengths, from 1,000 to 5,000 mcg, all of which contain the active form of methylcobalamin. Regardless of which strength you pick, the serving size is still one capsule, so you don’t have to struggle with taking a bunch of pills if you have trouble with that. Kate Meier, USAW-L1, CF-L1, CPT, tried these and said they were easy to swallow with zero unexpected taste. 

There are minimal fillers and no unnecessary additives, and this B12 is non-GMO and gluten-free. Plus, the supplement is third-party tested and made in a cGMP-compliant facility. Dr. Bob Iafelice recommends it and calls it an “excellent B12” with no cons he can think of.

The customer service stands out, too. Nutricost offers a 60-day money-back guarantee. Even if you’ve opened the bottle, you can return it for a refund within 60 days if it doesn’t work for you or you don’t like the product for whatever reason.

Best Liquid B12 Supplement: Cymbiotika Liposomal B6 + B12 Liquid

Good for: Anyone looking for a supplement with superior absorption

Best Liquid B12

Cymbiotika Liposomal B6 + B12 Liquid

GGR Score: 4.5

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Product Highlights

• Organic blend of B12 and B6 
• Claims to contain the most advanced form of B12 for maximum absorption 
• Formulated to boost energy, improve mood, and support heart health
• Subscribe and save option
• Recommended to take 12 pumps daily

Pros & Cons

Pros

• Receives tremendously positive reviews
• Organic
• Bioactive
• Contains B12 and B6
• Tastes good

Cons

• Expensive
• 12 pumps a dose

Bottom Line

Cymbiotika’s Liposomal B12 and B6 dietary supplement is an organic blend of B12 in the form of methylcobalamin and adenosylcobalamin and B6 in the form of pyridoxine HCI providing 1,250 micrograms of B12 and 1.3 milligrams of B6 in addition to 1.2 milligrams of methylfolate and 100 micrograms of fulvic acid

Liposomal vitamins are packed with pockets of fat (called liposomes) to help enhance bioavailability and increase absorption rate³. This increased absorption rate is one of the reasons we love the Cymbiotika Liposomal B6 + B12 Liquid, but it goes beyond that, too. This supplement contains a combo of methylcobalamin and adenosylcobalamin—two forms of vitamin B12 that are bioidentical⁴ to the B12 that occurs naturally in animal foods (and humans). It also contains some other synergistic B vitamins, like B6 and folate, to help normalize levels without focusing too much on one specific vitamin.

As far as added ingredients go, there aren’t many here. Cymbiotika uses natural and organic ingredients whenever possible, and stays away from unnecessary fillers or additives. Supplements are third-party tested and certificates of analysis (COAs) with specific findings are available on the site. As a final step, all supplements go through a med review where a team of doctors give the final sign off on the ingredients, the quality, and the claims.

In terms of taste, GGR writer and expert product tester Lauren Strong, CPT, had good things to say about this Cymbiotika liquid. “It’s very fruity with its berry flavor but it’s not too sweet or fake tasting,” she said. “I like it and the flavor does go away pretty quickly so it doesn’t give you a weird aftertaste.” Lauren also noted that the bottle says “users may not experience noticeable side effects unless one is deficient in B12,” but that she’s been feeling totally normal.

Best B-Complex Supplement: Double Wood Vitamin B Complex

Good for: Those who want an easy-to-take liquid B-complex with B12

Best B-Complex

Double Wood Vitamin B Complex

GGR Score: 4.5

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Product Highlights

• Easy-to-take liquid drops
• Tart cherry flavor
• $0.33/serving
• 1,750 mcg B12
• 30-day money-back guarantee on first purchase

Pros & Cons

Pros

• Easy-to-take liquid form
• Robust B-complex with 1,750 mcg B12
• Third-party tested
• 30-day money-back guarantee

Cons

• Won't enjoy if you aren't a fan of tart cherry
• Exact servings are difficult to measure

Bottom Line

Double Wood Vitamin B Complex comes in a convenient and easy-to-take liquid form with a tart cherry flavor. This is a good option for people who don't like taking pills and prefer a flavored alternative.

There are a total of eight B vitamins, collectively called the B12 complex, that work together to keep you healthy. Many people are deficient in more than one⁵, so it can often be beneficial to take a supplement that has effective doses of more than just vitamin B12 to cover your bases.

Double Wood’s Vitamin B Complex has 1,750 mcg of vitamin B12 in the very bioavailable form of methylcobalamin, plus vitamins B6, B9, B3, and B7. This combo helps support natural energy production—to be clear, it doesn’t give you a boost of energy like a pre-workout, but it can help provide your body with sustained energy as long as you’re consistent with it.

We also love that this supplement comes in liquid form with just a single dropper serving. With some other supplements, you have to take a bunch of capsules. This one is easy to take and it tastes good, but it doesn’t have artificial added ingredients. It has natural flavors and is sweetened only with organic stevia.

All bottles also come with a certificate of analysis (COA)—a third-party lab report that proves the supplement contains exactly what the brand says it does (something that can’t be said for all supplements). The COA is linked on the website, so you can easily access it whenever you need to. That’s a level of transparency that we can stand behind.

Best Vegan B12 Supplement: HUM Nutrition B12 Turbo

Good for: Anyone following a vegan diet or plant-based diet

Best Vegan

HUM B12 Turbo

GGR Score: 4.25

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Product Highlights

• Clean label project certified
• 1,000 mcg of B12 and 30 mg of calcium per tablet
• Claimed to boost energy levels and support nervous system function and metabolism
• Discounts for first-time buyers

Pros & Cons

Pros

• Easy-to-swallow small tablets
• Clean ingredients
• 3rd-party validated
• Vegan
• No artificial colors, sweeteners, flavors, or preservatives

Cons

• Reportedly poor packaging
• One review stating there was a bad taste

Bottom Line

The HUM B12 Turbo tablets contain 1,000 micrograms of B12 and 30 milligrams of calcium, are vegan-friendly, and derived from clean ingredients.

Unless you’re eating a lot of fortified cereals or nutritional yeast, long-term vegans and vegetarians⁶ have an increased risk of developing a vitamin B12 deficiency. That’s because the vitamin is found in the highest amounts in animal products. 

Yet some B12 supplements contain gelatin or other ingredients that make them an unsuitable choice for vegans. The Hum Nutrition B12 Turbo takes both of these things into account. Not only does it contain a fully vegan-friendly ingredient list, it offers B12 in the form of methylcobalamin—one of the most highly bioavailable forms. It also contains a small amount of calcium, which enhances B12 absorption⁷ and ensures the vitamin can actually make it past your digestive system.

HUM prioritizes inactive ingredient quality, too. All supplements are gluten-free, and tested regularly to ensure that they never exceed gluten levels as outlined by the FDA. The supplements are also free from artificial colors, sweeteners, flavors, and preservatives, and never include what HUM calls the “tricky 12”—various ingredients, like titanium dioxide and high-fructose corn syrup, in some commercial supplements that can actually pose health risks. Each supplement is also non-GMO certified and made in Good Manufacturing Process (GMP) compliant facilities, which basically means the purity, strength, and composition is regularly verified. 

Best B12 Gummies: Olly Daily Energy Gummies

Good for: Those who prefer gummies over capsules or liquid

Best Gummies

Olly Daily Energy Gummies

GGR Score: 4.25

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Product Highlights

• Daily gummy vitamin 
• Claimed to support natural energy production 
• Tropical passion flavored 
• 300 mcg of B12 and 30 mg CoQ10
• Slow-acting formula

Pros & Cons

Pros

• Reviewers like the taste
• Reportedly improves energy without causing jitters
• Caffeine-free
• Subscribe and save option

Cons

• Contains sugar and glucose syrup
• Effects may take weeks or months to feel
• 30 mg is a low dose of CoQ10

Bottom Line

The OLLY Daily Energy Gummies are a slow-acting daily gummies providing 300 micrograms of B12 in the form of cyanocobalamin, 100 milligrams of Goji berry juice powder, and 30 milligrams of Coenzyme Q10 (ubiquinone).

It doesn’t really matter how old you are; sometimes you just need a gummy vitamin instead of capsules. Unfortunately, gummies are notorious for less-than-stellar ingredients like artificial colorings and flavorings and high-fructose corn syrup. The Olly Daily Energy Gummies raise the bar though. 

They do have pure sugar in the form of glucose syrup and beet sugar, which is really just white sugar under an admittedly misleading name. However, some of the sweetness comes from orange juice concentrate, while natural carrot and blueberry juices give them their pinkish hue. In other words, the ingredient list is pretty good as far as gummies go.

Each serving (that’s two gummies) contains 300 micrograms of vitamin B12, as well as 100 milligrams of goji berry juice powder and Coenzyme Q10 (CoQ10). This combo is designed to boost energy, and CoQ10⁸ has also been linked to heart and immune health and may even help with migraines. While we certainly don’t think this will take the place of your pre-workout, a little extra caffeine-free energy boost doesn’t hurt.

Our tester and certified personal trainer Amanda Capritto, CPT, CES, CNC, CF-L1, CSNC, fell in love with these gummies and would eat them all day if she could. “They taste like fruit snacks!” she says.

Best High-Dose B12 Supplement: Bulletproof Methyl B12 5,000 mcg Lozenges

Good for: Those who need a higher daily dose, or prefer a lozenge

Best High-Dose B12

Bulletproof Methyl B-12 Tablets

GGR Score: 3.75

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Product Highlights

• 5,000 mcg of Methylcobalamin (Methyl B12) per lozenge
• Recommended to chew or dissolve in mouth 
• Spearmint flavored
• Reported to be highly bioavailable
• Designed to improve energy and nerve function
• Subscribe and save option, free shipping over $49.00

Pros & Cons

Pros

• 30-day 100% satisfaction guarantee
• Reportedly tastes good
• Science-based ingredients
• Users state there's a noticeable improvement in energy
• Vegan

Cons

• Slightly more expensive than competitors
• Couple of reports of increased anxiety

Bottom Line

Bulletproof’s Methyl B-12 supplement provides 5,000 micrograms of bioavailable methyl B12 and is designed to improve energy and nerve function.

If you’re really deficient in vitamin B12, you may need a higher dose supplement to help normalize your levels. This option from Bulletproof offers 5,000 of highly bioavailable methylcobalamin per serving in an extremely convenient package; it’s a tiny lozenge that you can either chew or let dissolve right on your tongue—and it has a natural spearmint flavor so it can freshen your breath in the process (a win-win).

In addition to a very minimal ingredient list, all Bulletproof supplements are soy-, dye-, and gluten-free. They’re also non-GMO and offered in clinical doses—meaning they have active ingredients that are higher than the daily average. However, there’s not a lot of transparency about third-party testing or verifications, so you’ll have to be willing to take the company at its word here.

GGR Head of Content Nicole Davis, CPT, PN1-NC, tested out the Bulletproof B12 and found the texture similar to a tum. The flavor was minty but not overpowering, and overall she thought the small lozenge was easy to get down.

Other B12 Supplements We Researched

Nature’s Bounty Vitamin B12: This is the most popular B12 supplement on Amazon, but it has a questionable ingredient list combined with a synthetic form of vitamin B12. It might do the trick for you, but all things considered, we just think there are better options out there.

Nature’s Bounty Quick Dissolve Vitamin B12: Another option from Nature’s Bounty, this one also has a questionable ingredient list that includes sucralose, which may (or may not) have some harmful health effects⁹. Because there are so many cleaner, more highly bioavailable, options out there, we decided to leave this one off the list.

Amazon Basics Vitamin B12 Gummies: These raspberry-flavored gummies are intriguing. They’re made with natural forms of vitamin B12 and have an impressive ingredient list of mostly organic components. Ultimately, they didn’t make the list because we like the energy combo in the Olly gummies better, but we think these are a worthwhile candidate.

How We Picked and Tested the Best B12 Supplements

First and foremost, we got expert advice from registered dietitians and other nutritional experts on what makes a good vitamin B12 supplement. While answers varied slightly, the general consensus was that the supplement should have a bioavailable form of vitamin B12 in dosages that could work for a wide variety of needs. 

Methodology

We narrowed down our selections of the best B12 supplements via our GGR supplement testing methodology, taking into account forms of B12, ingredients, and transparency among other criteria.

We chose to recommend varying forms of vitamin B12 to accommodate different needs. We also chose different delivery systems—you’ll find capsules, soft gels, lozenges, and liquid on this list—to appeal to a wide variety of people. Some have no problem swallowing pills and others would prefer not to. We heard you and made sure there was an option for you on this list.

The experts we interviewed also really emphasized the importance of a clean ingredient list. Many supplements are full of undesirable fillers, artificial flavors and colors, and sugar. Those ingredients aren’t necessary to the integrity of the product, so we chose brands that skipped them and kept things as minimal as possible (while still offering an effective supplement). 

We also considered brand reputation. While the FDA oversees the language supplement companies are allowed to use, there isn’t a ton of regulation beyond that. Basically, it’s on the company to not make false claims about potency and purity, but some don’t follow that honor code. 

To help you weed through the millions of subpar supplements out there, and to help protect your well-being, we chose only brands that are transparent about how their supplements are made and where their ingredients come from. Most of the brands that made our list do third-party testing and have that testing data available to you on their website.

Benefits of Vitamin B12 Supplements

Vitamin B12 deficiency or insufficiency affects about 6% to 20% of the general population, and is even more prevalent in elderly adults¹⁰ and those who follow a vegan or vegetarian diet. Low levels of vitamin B12 can cause a wide variety of symptoms, from fatigue and shortness of breath to a red tongue, mouth ulcers, and pins and needles in your extremities.

“Difficulty seeing, irritability, depression, and mental decline such as with memory or judgment can also be symptoms of vitamin B12 deficiency,” says Ashley Kitchens, MPH, RDN, adding that “If left untreated, vitamin B12 deficiency can cause irreversible damage.”

There’s also some evidence that vitamin B12 supplements can promote cardiovascular health¹¹, especially when combined with other B vitamins for a synergistic effect.

Vitamin B12 supplements are a way to fill in the gaps between what you’re getting from your diet and what you need to take in daily. They can help normalize levels in people who are already deficient, or minimize the risk of becoming deficient in the first place. 

Dosing and Interactions

The National Institutes of Health (NIH) Office of Dietary Supplements¹² recommends that adults over the age of 19 get at least 2.4 micrograms of vitamin B12 daily. If you’re pregnant or breastfeeding, those numbers jump to 2.6 and 2.8 micrograms, respectively.

However, supplements often have much higher doses because you only absorb a fraction of what’s in them. 

“It’s recommended to supplement with at least 50 micrograms (mcg) of vitamin B12 daily. This is higher than the recommended dietary allowance (the estimated amount of a nutrient needed per day for health maintenance), which is 2.4 mcg daily, because your body only absorbs about 2% of vitamin B12 at doses of 500 mcg,” Ashley says.

If you do the math, that means you’d be absorbing about 10 micrograms from a 500-microgram supplement. 

This number can also vary depending on your health status and how well you absorb vitamin B12. For example, intrinsic factor¹³, which is a protein that’s made by the cells in the lining of your stomach, helps your intestines absorb vitamin B12 and some people produce more than others. Taking proton-pump inhibitors can also affect B12 absorption because they suppress stomach acid¹⁴ which can reduce absorption rate.

Because there are a lot of nuances to consider, the proper dosing for you really depends on your individual needs and current vitamin B12 status. If you’re not sure how much you should be taking, it’s worth a discussion with your doctor or a qualified nutrition professional that knows your background and medical history. 

There are also some potential interactions¹⁵ to consider. Certain medications, including aminosalicylic acid, colchicine, metformin, and proton pump inhibitors can limit your body’s ability to absorb vitamin B12. Taking vitamin C supplements alongside vitamin B12 can also inhibit absorption. If you’re on medications or taking other supplements, make sure to check with your healthcare provider before adding anything new.

That being said, vitamin B12 supplements are generally considered safe at the right dosages. If you take too much, you may experience some side effects like headache, nausea/vomiting, diarrhea, fatigue, weakness, and tingling in the hands and feet. But, toxicity is almost unheard of¹⁶.

Buying Guide: What to Look for in a B12 Supplement

The supplement industry is a difficult one to navigate. We picked out some really great vitamin B12 supplements for you, but you should consider the following when narrowing down your choice.

Type of Vitamin B12

Vitamin B12 supplements typically come in three forms: methylcobalamin, adenosylcobalamin, and cyanocobalamin. The first two are natural forms that mimic what’s found in food, and the third is a synthetic form. Many experts recommend the natural forms for better absorption, but cyanocobalamin can be more shelf-stable, according to Ashley. There’s no one right answer here, but consider absorption versus shelf life when making your choice.

Ingredients 

B12 is the active ingredient in all vitamin B12 supplements, but you need to consider the inactive ingredients, too. These are additives and fillers that may add flavor or increase the shelf life of your supplement. When choosing a vitamin B12, try to pick one with as few inactive ingredients as possible. As a general rule: The cleaner the ingredient list, the better.

Delivery Method 

Vitamin B12 comes in several forms, like soft gels, capsules, chewables, and liquid. Some studies show that liquid supplements taken under the tongue (also called sublingual supplements) are the most bioavailable, but any form can help normalize your levels. Decide which delivery system works best for you before purchasing.

Testing

The supplement industry has gotten out of control. There are thousands of options on the market and many of them aren’t even what they claim¹⁷. To make sure you’re getting what you think you are, look for B12 supplements that are third-party tested or verified by national organizations like the USP or NSF.

Best B12 Supplements: FAQs

These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any diseases.

References

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6. Pawlak, R, Lester, SE, Babatunde, T. The prevalence of cobalamin deficiency among vegetarians assessed by serum vitamin B12: a review of literature. Eur J Clin Nutr. 2014;68(5):541-548. doi:10.1038/ejcn.2014.46
7. Linus Pauling Institute. Vitamin B12.
8. Saini R. Coenzyme Q10: The essential nutrient. J Pharm Bioallied Sci. 2011;3(3):466-467. doi:10.4103/0975-7406.84471
9. Bueno-Hernández N, Esquivel-Velázquez M, Alcántara-Suárez R, et al. Chronic sucralose consumption induces elevation of serum insulin in young healthy adults: a randomized, double blind, controlled trial. Nutr J. 2020;19(1):32. doi:10.1186/s12937-020-00549-5
10. Ankar, A, Kumar, A. Vitamin B12 deficiency. 2022. 
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13. National Library of Medicine Medline Plus. Intrinsic factor. 2022.
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Lindsay Boyers, CN

Lindsay Boyers is a functional nutritionist, writer, and editor with over a decade of experience in online media. She's written 14 books and hundreds of articles on fitness, wellness, nutrition, and lifestyle. Lindsay holds certifications in holistic nutrition, functional nutrition, and professional food safety, as well as a B.S. in food in nutrition.

Further reading

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