Vitamin B12
What’s New This Month
- Energy: NIH states that B12 has no benefit for performance without a deficiency; we rate the energy claim Doubtful. 1
- Mood: A 2026 pool of 4 trials found no change in depression or mood scores. 2
- Kidneys: In a 2026 trial of 35 adults with low B12, kidney filtration fell in the 2,000 mcg group. 3
- Recalls: FDA records list two 2025 recalls of B12 gummies for undeclared peanut and a 2026 recall of B12 sprays. 4 5 6
Overview
Vitamin B12 (cobalamin) helps make red blood cells and keep nerves healthy. Adults need 2.4 mcg a day. 1 Low B12 affects about 2% of people in high-income countries, and up to 69% where animal foods are scarce. 7
It is sold as cyanocobalamin, methylcobalamin or hydroxocobalamin. Labels claim energy, heart and nerve health, memory, mood and healthy homocysteine (a blood marker).
How We Researched It
We rate each marketing claim with a modified version of GRADE, the system medical researchers use to say how sure we can be (i.e., high, moderate, low or very low), and check each trial with the Cochrane risk-of-bias tool, which asks whether a study’s design could skew its results. For vitamin B12 we screened about 40 records and used 29, mostly published from September 2022 through October 2026. We also checked 10 regulators and safety databases. We read Cochrane reviews only through summaries.
Research NotesTop three benefits
Deficiency Correction and Prevention GRADE: Moderate
Pooling 16 studies (6,098 people), B12 raised blood levels by about 403 pg/mL and lowered homocysteine (a blood marker) by 4.8 µmol/L. Pills matched shots. 8
Bias check: These are blood markers, not symptoms. The review reports no outside funding and no commercial ties. 8
Nerve Health GRADE: Moderate
A review of 10 trials found nerve symptoms improve when deficiency is clear-cut, but not when it is mild. 9 In 35 adults with diabetic nerve pain and low B12, pain fell on 1,000 and 2,000 mcg. 3
Bias check: The 2026 trial had no placebo group, and its nerve disability score did not change. 3
Fatigue in B12 Deficiency GRADE: Low
We found no trial of fatigue in people who are low in B12. NIH lists fatigue among the signs of deficiency. 1
Bias check: There is no trial to check, so the rating rests on reference text, not on study results.
Benefit Evaluation
| Claim | Claim Verdict | Research Confidence | Supporting Evidence | Safety Risk | Product Quality | FactStack™ Rating |
|---|---|---|---|---|---|---|
| Deficiency Correction and Prevention | Supported | Moderate | Convincing | Within Limits | Within Limits | Favorable |
| Nerve Health | Supported | Moderate | Convincing | Within Limits | Within Limits | Favorable |
| Fatigue in B12 Deficiency | Promising | Low | Promising | Within Limits | Within Limits | Favorable |
| Cognition | TBD | Low | TBD | Within Limits | Within Limits | Caution |
| Heart Health | TBD | Very Low | TBD | Within Limits | Within Limits | Caution |
| Metformin Support | TBD | Low | TBD | Within Limits | Within Limits | Caution |
| Birth Outcomes and Neural Tube Defects | TBD | Very Low | TBD | Within Limits | Within Limits | Caution |
| Energy | Doubtful | Low | Doubtful | Within Limits | Within Limits | Warning |
| Mood | Doubtful | Low | Doubtful | Within Limits | Within Limits | Warning |
| Bone Health and Fracture | Doubtful | Very Low | Doubtful | Within Limits | Within Limits | Warning |
What Sellers Say vs. What Studies Show
| “B12 gives you energy.” | Not unless you are low. NIH says B12 has no benefit for performance without a deficiency. 1 |
| “Methyl or under-the-tongue B12 absorbs better.” | NIH finds no difference in effect between swallowed and under-the-tongue B12. 1 |
| “You need shots to fix low B12.” | In pooled studies, pills raised blood levels as much as shots. Severe cases with nerve symptoms need a doctor. 8 |
| “B12 lifts your mood.” | Pooled trials found no change in depressive symptoms. 10 2 A 2026 conference abstract suggests possible benefit only when B12 starts low, with no numbers given. 11 |
| “B12 sharpens memory.” | Pooled across 8 trials, memory did not change. Most people in them had normal or borderline B12. 10 B6, folate and B12 together gave a very small cognition gain in 17 trials of adults 60 and over. 12 Lower active B12, even in the normal range, went with slower processing in 231 older adults, which cannot show cause. 13 |
| “More is always better.” | In one 35-person trial, kidney filtration fell on 2,000 mcg. Years of 55 mcg or more were linked to lung cancer in men, and more so in smokers. 3 14 One 2025 review proposes about 20 mcg a day as a ceiling; it is a proposal, and its lead author reports industry fees. 15 |
Trial ParametersIf you try it
| Who | Vegans, adults over about 60, people on metformin or acid reducers, weight-loss surgery patients, or nitrous oxide users. Test first if you have symptoms. 16 |
| Dose | The daily need is 2.4 mcg. NICE advises at least 1,000 mcg a day by mouth when poor absorption is the cause. 1 16 |
| Ceiling | NIH sets no upper limit. Do not assume 2,000 mcg beats 1,000 mcg if kidney function is reduced. 1 3 |
| Duration | Male smokers without a deficiency should avoid 55 mcg or more a day for years. No other duration limit is stated. 14 |
| Form | A plain swallowed tablet; under-the-tongue forms work the same. Recent B12 recalls hit gummies and a spray. 1 4 6 |
| Ask First | Smokers; reduced kidney function; cobalt or B12 sensitivity; early Leber’s disease (an inherited eye disease); peanut allergy with gummies; severe anemia or nerve symptoms. |
How to Take It
| Pick a plan | If a test confirms low B12 and poor absorption is the cause, NICE advises at least 1,000 mcg a day by mouth. If you have symptoms, test first. 16 |
| Time of day | Not reported. |
| With food | Not reported. Only about 2% of a 500 mcg dose and 1.3% of a 1,000 mcg dose is absorbed. 1 |
| What to expect | In deficiency, red-cell counts start rising in 3 to 5 days and hemoglobin is normal in about 2 months. 17 |
| How to take | Swallow a plain tablet or capsule each day. B12 can make a blood test hard to read, so test before you start. 16 |
Works With / Don’t Mix With
✓ Works with
Testing first. NICE advises testing people who have a common symptom and a risk factor before starting B12. 16
Other routes. In a 2026 trial of 153 adults with B12-deficiency anemia, nasal, IV and IM routes raised hemoglobin 1.8 to 2.5 g/dL alike; there was no oral arm. 18
Metformin users who are low. In a 2026 trial of 50 people, a sucrosomial B12 raised their levels within a week. 19
⚠ Ask first / don’t mix
Metformin can reduce B12 absorption; users had about 3 times the odds of deficiency. Ask about testing. 1 20
Acid reducers such as proton-pump inhibitors and H2 blockers can reduce B12 absorption. 1
Gummies, if you have a peanut allergy. Two 2025 B12 gummy recalls were for undeclared peanut. 4 5
Manufacturer Recalls & WarningsLast 36 months, newest first
| Date | Maker / Brand | Product | Action | Src |
|---|---|---|---|---|
| Apr 2026 | Wellnov Supplements LLC (Chandler, AZ) | Liposomal B12 Spray; Liposomal D3+B12 Spray | FDA Class II: manufacturing lapses with a possible botulism-germ concern; 86 bottles. Terminated 10 Jul 2026. Spray form, not a pill. | 6 |
| Jun 2025 | Vitalabs, Inc. (Black Girl Vitamins; Rise-N-Shine) | B12 raspberry gummies | FDA Class II: undeclared peanuts; 9,657 bottles in IL and NJ. Status: Completed. | 5 |
| Jun 2025 | Vita Warehouse Corp. (Welby; Berkely Jensen; VitaGlobe; Vita Labs) | B12 gummies, lot 248046601 | FDA Class I: undeclared peanut; 40,522 bottles plus 582,000 gummies, nationwide. Terminated 28 Oct 2025. | 4 |
Where to Buy
We compare products side-by-side not just on price, but on whether NSF lists the product as NSF/ANSI 173 Contents Certified (an independent lab confirms the label matches the contents), whether it is NSF Certified for Sport, whether USP lists it as USP Verified, and whether the seller says it is manufactured in the USA. We leave out a brand’s products for this supplement when, in the last 36 months, the FDA took action against that brand over this supplement (a Class I or II recall, a warning letter, an import alert or an advisory letter). We also leave out any brand with an FDA Class II recall or warning letter on any product. We also leave out any product named in a California Prop 65 notice or a non-US recall, along with that brand’s products of the same ingredient and form. Brands with other actions stay listed and are marked in the Recall Screen column. Our goal remains to provide you, the Consumer, with the information and data necessary to make an informed purchasing decision. Prices reflected below are static and subject to change.
Ratings above describe the ingredient’s research, not any product listed below.
| # | Retailer | Product | Price | NSF 173 | NSF Sport | USP | Mfg. in USA (per seller) | Recall Screen | Affiliate link |
|---|---|---|---|---|---|---|---|---|---|
| 1 | iHerb | Thorne, Vitamin B12, 90 Capsules (100 mcg per Capsule) | $34.00 | ✓ | ✓ | ✓ | ✓* | View on iHerb ↗ | |
| 2 | Amazon | Nature's Wonder Vitamin B12 1000 mcg Timed Release, 150 Tablets | Check Price | ✓ | ✓ | ✓ | View on Amazon ↗ | ||
| 3 | Amazon | NatureWise Vitamin B12 1000 mcg, 60 Softgels | Check Price | ✓ | ✓ | ✓ | View on Amazon ↗ | ||
| 4 | Amazon | 21st Century Vitamin B-12 1000 mcg Prolonged Release, 110 Tablets | Check Price | ✓ | ✓ | ✓* | View on Amazon ↗ | ||
| 5 | Amazon | Nature Made Vitamin B12 1000 mcg, 150 Softgels | Check Price | ✓ | ✓ | ✓ | View on Amazon ↗ | ||
| 6 | HerbsPro | Solgar, Vitamin B12, 100 Mcg, 100 Tabs | $6.52 | ✓ | ✓ | View on HerbsPro ↗ | |||
| 7 | Green's Nutrition | Nutricost Vitamin B12 Methylcobalamin 30 Caps | $9.99 | ✓ | ✓* | View on Green's Nutrition ↗ | |||
| 8 | HerbsPro | Solgar, Vitamin B12, 500 mcg, 100 V Caps | $10.49 | ✓ | ✓ | View on HerbsPro ↗ | |||
| 9 | Green's Nutrition | Bio Nutrition B-12 Sublingual 50 Tabs | $22.95 | ✓ | ✓* | View on Green's Nutrition ↗ | |||
| 10 | Green's Nutrition | Superior Source Vitamin B12 30 Tabs | $33.99 | ✓ | ✓ | View on Green's Nutrition ↗ |
Sources
1. Vitamin B12: Fact Sheet for Health Professionals. NIH Office of Dietary Supplements, updated 2 Jul 2025. ods.od.nih.gov/factsheets/VitaminB12-HealthProfessional/
2. Moroianu et al. Vitamin D and B12 in psychiatric disorders: systematic review and exploratory meta-analysis. Diseases 14(5):167, 2026. doi.org/10.3390/diseases14050167
3. Mansour et al. 1,000 versus 2,000 mcg oral methylcobalamin in type 2 diabetes with nerve damage and low B12: 16-week randomized trial. Journal of Nutrition 156(3):101368, 2026. doi.org/10.1016/j.tjnut.2026.101368
4. Recall H-0212-2025: Vita Warehouse Corp., B12 gummies (undeclared peanut). US Food and Drug Administration (openFDA food enforcement), Jun 2025; terminated 28 Oct 2025. api.fda.gov/food/enforcement.json?search=recall_number.exact:%22H-0212-2025%22
5. Recall H-0037-2026: Vitalabs, Inc., B12 raspberry gummies (undeclared peanuts). US Food and Drug Administration (openFDA food enforcement), Jun 2025; classified 10 Oct 2025. api.fda.gov/food/enforcement.json?search=recall_number.exact:%22H-0037-2026%22
6. Recalls H-0807-2026 and H-0806-2026: Wellnov Supplements LLC, liposomal B12 sprays. US Food and Drug Administration (openFDA food enforcement), Apr 2026; terminated 10 Jul 2026. api.fda.gov/food/enforcement.json?search=recall_number.exact:%22H-0807-2026%22
7. Yepes-Calderon et al. Vitamin B12 supplementation: is more always better? (narrative review). Nutrients 18(10):1597, 2026. doi.org/10.3390/nu18101597
8. Mazur et al. Sublingual, oral and intramuscular vitamin B12: systematic review and meta-analysis. Frontiers in Pharmacology, 2025. doi.org/10.3389/fphar.2025.1602976
9. Hamza Ali A et al. Vitamin B12 in overt and subclinical deficiency: systematic review of 10 randomized trials. Cureus 17(5):e83668, 2025. doi.org/10.7759/cureus.83668
10. Alzahrani et al. Vitamin B12 and memory and depressive symptoms: meta-analysis of randomized trials. Cureus 16(11):e73350, 2024. doi.org/10.7759/cureus.73350
11. Zeilstra et al. Vitamin B12 for depression: systematic review (conference abstract). European Psychiatry 69(Suppl 1):S633, 31 Jul 2026. doi.org/10.1192/j.eurpsy.2026.11385
12. Meta-analysis of 17 trials of B6, folate and B12 combined and cognition in adults 60 and over. Nutrition Reviews, Dec 2025. pubmed.ncbi.nlm.nih.gov/40966571/
13. Beaudry-Richard A et al. Active vitamin B12 and brain structure and function in 231 healthy older adults. Annals of Neurology 97(6):1190, 2025. pubmed.ncbi.nlm.nih.gov/39927551/
14. Brasky TM, White E, Chen CL. Long-term B-vitamin supplement use and lung cancer risk (VITAL cohort). Journal of Clinical Oncology 35(30):3440, 2017. doi.org/10.1200/JCO.2017.72.7735
15. Obeid R. A framework for vitamin B12 supplement doses (narrative review). Current Nutrition Reports 14(1):32, 2025. pubmed.ncbi.nlm.nih.gov/39939550/
16. Vitamin B12 deficiency in over 16s: diagnosis and management (NG239). National Institute for Health and Care Excellence (NICE), Mar 2024. www.nice.org.uk/guidance/ng239
17. Vitamin B12 Deficiency: treatment and management. Medscape Drugs & Diseases, Checked 10 Oct 2026. emedicine.medscape.com/article/204066-treatment
18. Singh SK et al. Intranasal, intramuscular and intravenous vitamin B12 for B12-deficiency anemia: randomized trial of 153 adults. American Journal of Hematology 101(9):2343, 2026. pubmed.ncbi.nlm.nih.gov/42393020/
19. Conti et al. Sucrosomial oral vitamin B12 in metformin users with low B12: placebo-controlled randomized trial. Pharmaceutics 18(2):237, 2026. doi.org/10.3390/pharmaceutics18020237
20. Kakarlapudi et al. Metformin and vitamin B12 deficiency: meta-analysis of 17 observational studies. Cureus 14(12):e32277, 2022. doi.org/10.7759/cureus.32277
