The 8 Best B12 Supplements of 2024

Where We Stand

Nature Made Sublingual B-12 Lozenges is our top pick because they are budget-friendly, independently verified, the preferred form of B12. For a liquid option with easily adjustable dosing, try Vitacost Liquid Vitamin B12.

Who Can Benefit From B12 Supplements

B12 supplements are helpful in treating and preventing those with a deficiency. The following groups of people are at risk for deficiency and may benefit from a supplement. 

• Vegans and Vegetarians. “Many vegans and vegetarian eaters don’t take in enough vitamin B12. This is because many sources are animal-based, and the nutrient isn’t always easy to get enough of on a plant-based diet,” says plant-based dietitian Amy Gorin, MS, RDN.
• Older Adults. People over the age of 65 may have lower levels of stomach acid, which is required to break down and absorb B12. If there is not enough stomach acid, the B12 cannot combine with intrinsic factor in the stomach, and this step is needed to absorb B12 in the small intestine.
• People with certain digestive disorders or illnesses. People with digestive disorders affecting the stomach and small intestine such as Crohn’s, small intestinal bacterial overgrowth (SIBO), H.Pylori, and Celiac disease may not be able to properly absorb B12.
•  People who have had bariatric surgery. Bariatric surgeries such as the roux-en-y gastric bypass put patients at risk for B12 (among other nutrient) deficiency. This is related to lower intrinsic factor production, lower stomach acid, and bypassing a part of the small intestine called the duodenum, which is the main site of B12 absorption.
• People taking certain medications. Some medications, especially those aimed to treat gastroesophageal reflux disease (GERD), reduce stomach acid content which can increase risk for B12 deficiency. Metformin, a common diabetes medication, is also associated with B12 deficiency. 
• People who have a variant of the MTHFR gene: “People who have a variant of the MTHFR gene mutation might need to take B12, since this gene mutation interferes with the body’s natural ability to use certain B vitamins including B12,” says Volpe.

Who Shouldn’t Take B12 Supplements

In general, B12 supplements are safe for most people. Vitamin B12 is water-soluble, which means that your body will excrete what it doesn’t need through urine. However, consuming excess B12 does not provide any additional benefits. So, if you regularly consume animal-based foods like meat, fish, poultry, eggs, and dairy (and do not have a medical condition that affects B12 absorption), you likely do not need a B12 supplement.

The following groups of people should consult a healthcare professional before consuming B12 supplements:

• People taking certain medications. Both gastric acid inhibitors (medications to treat GERD) and Metformin (used to treat diabetes) may reduce the body’s ability to absorb vitamin B12, including from certain supplements. If you take these medications and are deficient in B12, you may need to consider a sublingual supplement or talk to a healthcare provider about B12 injections.
• People with a sensitivity to cobalt. Cobalt is present in cyanocobalamin, the most common form of B12 supplements. If you have a known cobalt allergy, it’s recommended that you take a different form of B12, like methylcobalamin.

How We Select Supplements

Our team works hard to be transparent about why we recommend certain supplements; you can read more about our dietary supplement methodology here. 

We support supplements that are evidence-based and rooted in science. We value certain product attributes that we find to be associated with the highest quality products. We prioritize products that are independently verified and certified by one of three independent certifiers: USP, NSF, or ConsumerLab.com. 

It’s important to note that the FDA does not review dietary supplements for safety and effectiveness before they go to market. Our team of experts has created a detailed, science-backed methodology to choose the supplements we recommend.

What to Look For

Independent Verification 

Supplements that are independently verified are sent to a lab where they are tested for purity and potency to ensure they contain what they say they contain and do not contain any potential contaminants. Trusted independent certifications include ConsumerLab.com, NSF, USP, among others. However, these certifications can be difficult to obtain and expensive for manufacturers, so many companies choose not to get their products tested. If you are selecting a supplement that does not have independent verification, we recommend choosing a trusted brand that does rigorous internal testing.

Types of B12 

There are four different forms of vitamin B12: cyanocobalamin, methylcobalamin, adenosylcobalamin, and hydroxocobalamin. According to the National Institutes for Health, there is no evidence to suggest that absorption rates vary significantly between forms. Recent research comparing the two most common forms (methylcobalamin and cyanocobalamin) is limited.

Vitamin B12 supplements are available in capsules, sublingual, chewable, liquid, spray, as well as perscription injections. The best form for you will depend on the reason for deficiency.

“People who are dealing with low B12 levels due to poor stomach acid absorption may benefit most from a B12 shot or sublingual version of a B12 supplement since these delivery methods bypass the gut,” says Volpe. She adds, “You’ll start absorbing it in your mouth instead of waiting for it to be activated by your stomach acid and released through your small intestine—which may not be working effectively.”

Vitamin B12 is also found in combination with other B-vitamins as well as in multivitamins and prenatal vitamins. “When there are multiple B vitamin deficiencies or other vitamin or mineral deficiencies uncovered, I typically recommend seeking out a B complex or multivitamin or prenatal containing methylated B12 versus just taking a B12 supplement,” says Volpe.

Ingredients & Potential Interactions

It is essential to carefully read the ingredient list and nutrition facts panel of a supplement to know which ingredients and how much of each ingredient is included relative to the recommended daily value of that ingredient. Please bring the supplement label to a healthcare provider to review the different ingredients contained in the supplement and any potential interactions between these ingredients and other supplements and medications you are taking.

How Much To Take 

The Recommended Daily Allowance for adults for vitamin B12 is 2.4 micrograms. Pregnant and lactating people need 2.6 micrograms and 2.8 micrograms, respectively. Most supplements come in much higher doses because the body can’t absorb everything consumed through supplements. The recommended dose for those with deficiency is typically 1,000 to 2,000 micrograms daily. It’s also recommended that people who have had bariatric surgery take 1,000 micrograms daily.

It’s estimated that absorption rates for those containing less than 2 micrograms of vitamin B12 is about 50 percent. That significantly decreases with higher doses. Supplements with 500 micrograms of vitamin B12 are absorbed at about a 2 percent rate and 1,000 – 2,000 micrograms are absorbed at only 1.3 percent. That means if you take a supplement that contains 2,000 micrograms of vitamin B12, you’re likely absorbing about 26 micrograms. 

There is currently no established tolerable upper limit (UL) for vitamin B12, as there is a low risk of toxicity. Because it’s a water-soluble vitamin, your body excretes what it doesn’t need in urine.

Our Experts

We also consulted with the following Registered Dietitians:

• Amanda Lane, MS, RDN, CDCES, dietitian specializing in dialysis at Plant-Powered Kidneys Renal Nutrition Services
• Jenna Volpe, RDN, LD, CLT, functional dietitian and founder of Whole-istic Living
• Amy Gorin, MS, RDN, inclusive plant-based dietitian and owner of Plant Based with Amy