Vitamin B12 supplements, compared
12 products we’ve reviewed list vitamin b12 as a key ingredient. Here’s what it does, what the research uses — and how much each product actually contains.
What it is
Needed for nerve function and red blood cell formation. It occurs naturally only in animal foods, so vegans — and many older adults, who absorb it less well — rely on fortified foods or supplements.
What the research uses
Adults need 2.4 mcg a day. There is no upper limit because vitamin B12 is considered safe even at high doses, and only a small fraction of a large dose is absorbed.
Educational information, not medical advice. Talk to a healthcare professional before starting a supplement, especially if you are pregnant, nursing or take medication.
Every product, dose by dose
| Product | Vitamin B12 per serving | Form | Score |
|---|---|---|---|
 USP Verified | 18 mcgVitamin B12 (as cyanocobalamin) | Tablet | 8.5 |
 | 1,000 mcgVitamin B12 (as cyanocobalamin) | Tablet | 8.5 |
 NSF Certified for SportNSF Contents Certified | 600 mcgVitamin B12 (as methylcobalamin) | Capsule | 8.2 |
 | 6 mcgVitamin B12 (as cyanocobalamin) | Tablet | 8.0 |
 USP VerifiedNon-GMO Project VerifiedClean Label Project | 8 mcgVitamin B12 (as methylcobalamin) | Capsule | 7.5 |
 NSF Certified for Sport | 680 mcg DFE / 400 mcg / 5 mgMethylated B vitamins (folate as 5-MTHF, B12 as methylcobalamin, B6 as P5P) | Powder | 7.3 |
 NSF Contents Certified | 6 mcgVitamin B12 (as cyanocobalamin) | Gummy | 7.3 |
 | 100% DV per piece | Chewable | 7.2 |
 | 62 mg vitamin CVitamin C and B vitamins (B3, B5, B6, B12) | Stick pack | 7.0 |
 Third-party testedNon-GMO Project VerifiedClean Label Project | 40 mg (11 billion CFU at expiration)Probiotic Blend: Lactobacillus rhamnosus (LGG®) and Bifidobacterium animalis ssp. lactis (BB-12®) | Capsule | 7.0 |
 Clean Label Project | 12 mcgVitamin B12 (as methylcobalamin) | Liquid | 6.5 |
 cGMP facility | 1.2 mcg per gummy (50% DV) | Gummy | 5.2 |
Amounts are per serving as printed on each label. “Not disclosed” usually means the ingredient sits inside a proprietary blend.
Questions people ask
How much vitamin b12 do studies use?
Adults need 2.4 mcg a day. There is no upper limit because vitamin B12 is considered safe even at high doses, and only a small fraction of a large dose is absorbed.
Which vitamin b12 supplement scores highest?
In our reviews, Nature Made Multi for Him scores highest at 8.5/10, followed by Nature's Bounty Vitamin B-12 1,000 mcg (8.5) and Thorne Basic Nutrients 2/Day (8.2). Scores weigh efficacy, quality, value, experience and transparency — not just the dose.
How much vitamin b12 is in these products?
It varies by product and serving size — for example Nature Made Multi for Him (18 mcg), Nature's Bounty Vitamin B-12 1,000 mcg (1,000 mcg), Thorne Basic Nutrients 2/Day (600 mcg). The table above lists the amount per serving for every product we've reviewed.