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Vitamin B12 Supplements
Compare US vitamin B12 products by form, daily micrograms, serving schedule, price and testing status. Understand large %DV figures, 1,000–5,000 mcg products and when deficiency needs clinical assessment.
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Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Recognised certification
Manufacturer statement
Thorne product page states: "It is third-party tested for purity and quality" and NSF Certified for Sport registry confirms "Thorne® Vitamin B12" with product form Capsule, package size 60, serving size 1 capsule, and lot numbers 416646 / 416645 / 416898.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Testing evidence
Evidence status
Recognised certification
Manufacturer statement
Thorne product page states: "It is third-party tested for purity and quality" and NSF Certified for Sport registry confirms "Thorne® Vitamin B12" with product form Capsule, package size 60, serving size 1 capsule, and lot numbers 416646 / 416645 / 416898.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
US adult RDA and labeling Daily Value: 2.4 mcg. %DV is not the absorbed percentage. No upper limit is established. Our comparison band extends to 1,000 mcg, the upper end of typical standalone supplement doses described by NIH ODS. This is a practice-based boundary, not a safety limit; higher doses may be used for deficiency treatment. Read the dose guide ↓
Nutrasource registry page states: "IGEN™ Certified" and "This product has PASSED because it does not contain detectable amounts of genetically engineered GMO proteins and genes included in the IGEN™ testing panel."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Thorne product page states: "It is third-party tested for purity and quality" and NSF Certified for Sport registry confirms "Thorne® Vitamin B12" with product form Capsule, package size 60, serving size 1 capsule, and lot numbers 416646 / 416645 / 416898.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW Foods article title found on its own site: "NOW’s Testing of Methyl B-12 Brands on Amazon". This is a general testing-related claim/article, but I did not independently verify any third-party test/certification for this specific product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Amazon listing says: "QUALITY TESTED: Vitamin B12 lozenges are tested in independent laboratories for quality and purity to ensure product standards." I could not independently verify a product-specific third-party lab report or certifying-body registry entry for this exact product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutricost product page says: "Tested by Independent (3rd Party), ISO-Accredited Laboratories" and "Third-Party Tested †"; the B12 page also says "3rd party tested for potency and purity" and "Our products are 1st tested by us & then 3rd party tested as well to ensure safety, quality and purity."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Horbäach’s product page says: “We constantly source the best ingredients worldwide, test each individual product to ensure it meets our strict Quality Assurance Standards.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Seeking Health’s product page says “Third Party Tested,” and Seeking Health’s Quality Standards page says “Independent Certification” and links to a GMP certificate. Independently, NSF’s own Certified for Sport directory confirms a Seeking Health Hydroxo-Adeno B12 listing at https://nsfsport-prod.nsf.org/certified-products/listing-detail.php?id=1799088 (product page title: “Seeking Health, Hydroxo-Adeno B12, 2,000 mcg, 60 Lozenges”).
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Carlyle’s own manufacturing page says: “We conduct testing in our microbial lab, examining for purity, potency, and composition, to validate the identity of each of our ingredients.” The product page itself did not provide a product-specific COA or independent certification for this B12 item.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Swanson’s own quality page says: “All ingredients used in Swanson brand supplements require documentation from the supplier, including a Certificate of Analysis… Our ingredients are tested at various stages throughout the production process to verify purity and potency. All finished products are inspected by our Quality Control specialists and tested by independent third-party laboratories to ensure that each supplement contains exactly what’s stated on the label.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NatureWise product page states: "Product Facts: ... Contents Certified by NSF" and "The 1,000 mcg strength of this vitamin B12 is NSF-certified, which means its contents are thoroughly tested for accuracy and purity, and has been confirmed for no harmful levels of contaminants." NSF's own registry lists "Naturewise Vitamin B12 1000mcg Softgels" under NSF/ANSI Standard 173.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Source Naturals product page says: "cGMP Certified" and "Every supplement engineered in our labs"; it also has a FAQ link titled "How are your products tested?" but I did not find a product-specific third-party test/certification record for this item.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
USP’s registry lists “Nature Made Vitamin B12 1000 Mcg Softgels” under USP Verified Products, and USP explains that the USP Verified Mark means the product contains the ingredients listed on the label in the declared potency and amounts and has undergone laboratory testing and off-the-shelf testing.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site says the product is 'Lab Tested' and the brand promises 'all products meet rigorous safety and efficacy standards,' but I found no independently verifiable COA, lab report, or certifying-body registry entry for this specific product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site states: "The facility is certified to NSF/ANSI 455-2 Good Manufacturing Practices for Dietary Supplements, and raw materials and finished products undergo testing for identity, potency, purity and contaminants." It also says: "Third party tested for purity and accuracy, so what’s on the label is what you get."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Certificate of Analysis: Pure TheraPro Rx® BioActive B12 10mL — "Test Report Type: Third Party: Southern Element Labs"; results shown for vitamin B12 forms, gluten, microbiology, and heavy metals.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
XYMOGEN product page says: "We gladly offer certificates of analysis on request" and "our rigorous quality assurance, on-premises quality control laboratory testing for identity, strength, quality, and purity..." However, I did not find an independently verifiable COA for this specific product, and the NSF Certified for Sport registry result I found was for a different product (FIT Whey For Sport Cocoa), not this methylcobalamin product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutrasource registry page states: "IGEN™ Certified" and "This product has PASSED because it does not contain detectable amounts of genetically engineered GMO proteins and genes included in the IGEN™ testing panel."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Thorne product page states: "It is third-party tested for purity and quality" and NSF Certified for Sport registry confirms "Thorne® Vitamin B12" with product form Capsule, package size 60, serving size 1 capsule, and lot numbers 416646 / 416645 / 416898.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NOW Foods article title found on its own site: "NOW’s Testing of Methyl B-12 Brands on Amazon". This is a general testing-related claim/article, but I did not independently verify any third-party test/certification for this specific product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Amazon listing says: "QUALITY TESTED: Vitamin B12 lozenges are tested in independent laboratories for quality and purity to ensure product standards." I could not independently verify a product-specific third-party lab report or certifying-body registry entry for this exact product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Nutricost product page says: "Tested by Independent (3rd Party), ISO-Accredited Laboratories" and "Third-Party Tested †"; the B12 page also says "3rd party tested for potency and purity" and "Our products are 1st tested by us & then 3rd party tested as well to ensure safety, quality and purity."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Horbäach’s product page says: “We constantly source the best ingredients worldwide, test each individual product to ensure it meets our strict Quality Assurance Standards.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Seeking Health’s product page says “Third Party Tested,” and Seeking Health’s Quality Standards page says “Independent Certification” and links to a GMP certificate. Independently, NSF’s own Certified for Sport directory confirms a Seeking Health Hydroxo-Adeno B12 listing at https://nsfsport-prod.nsf.org/certified-products/listing-detail.php?id=1799088 (product page title: “Seeking Health, Hydroxo-Adeno B12, 2,000 mcg, 60 Lozenges”).
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Carlyle’s own manufacturing page says: “We conduct testing in our microbial lab, examining for purity, potency, and composition, to validate the identity of each of our ingredients.” The product page itself did not provide a product-specific COA or independent certification for this B12 item.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Swanson’s own quality page says: “All ingredients used in Swanson brand supplements require documentation from the supplier, including a Certificate of Analysis… Our ingredients are tested at various stages throughout the production process to verify purity and potency. All finished products are inspected by our Quality Control specialists and tested by independent third-party laboratories to ensure that each supplement contains exactly what’s stated on the label.”
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
NatureWise product page states: "Product Facts: ... Contents Certified by NSF" and "The 1,000 mcg strength of this vitamin B12 is NSF-certified, which means its contents are thoroughly tested for accuracy and purity, and has been confirmed for no harmful levels of contaminants." NSF's own registry lists "Naturewise Vitamin B12 1000mcg Softgels" under NSF/ANSI Standard 173.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Source Naturals product page says: "cGMP Certified" and "Every supplement engineered in our labs"; it also has a FAQ link titled "How are your products tested?" but I did not find a product-specific third-party test/certification record for this item.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
USP’s registry lists “Nature Made Vitamin B12 1000 Mcg Softgels” under USP Verified Products, and USP explains that the USP Verified Mark means the product contains the ingredients listed on the label in the declared potency and amounts and has undergone laboratory testing and off-the-shelf testing.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site says the product is 'Lab Tested' and the brand promises 'all products meet rigorous safety and efficacy standards,' but I found no independently verifiable COA, lab report, or certifying-body registry entry for this specific product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Manufacturer site states: "The facility is certified to NSF/ANSI 455-2 Good Manufacturing Practices for Dietary Supplements, and raw materials and finished products undergo testing for identity, potency, purity and contaminants." It also says: "Third party tested for purity and accuracy, so what’s on the label is what you get."
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
Certificate of Analysis: Pure TheraPro Rx® BioActive B12 10mL — "Test Report Type: Third Party: Southern Element Labs"; results shown for vitamin B12 forms, gluten, microbiology, and heavy metals.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
XYMOGEN product page says: "We gladly offer certificates of analysis on request" and "our rigorous quality assurance, on-premises quality control laboratory testing for identity, strength, quality, and purity..." However, I did not find an independently verifiable COA for this specific product, and the NSF Certified for Sport registry result I found was for a different product (FIT Whey For Sport Cocoa), not this methylcobalamin product.
Displayed points and weights are rounded; the total uses unrounded weights. Pending dimensions are excluded. Provisional scores may change after review.
One-time purchase prices; delivery and conditional discounts excluded. Daily cost uses the recorded label serving. Comparison amounts are not personal dose recommendations. Unknown Prime eligibility is not treated as confirmed.
Vitamin B12 forms explained
A chemical form and a delivery method are different things. The cards identify what is disclosed; they do not rank a form as universally best.
Methylcobalamin
One B12 form
Label term
Methyl B12
Compare
Full serving and schedule
An active-form label does not establish superior absorption or benefit for everyone.
Cyanocobalamin
One B12 form
Label term
Cyano B12
Compare
Amount and testing evidence
The body can convert it to active B12 forms. Do not dismiss it from the name alone.
Hydroxocobalamin
One B12 form
Also written
Hydroxycobalamin
Compare
Product and route
An oral product is not the same preparation or treatment as a prescribed injection.
Adenosylcobalamin
One B12 form
Often appears
In combination formulas
Check
Individual amounts if disclosed
A blend name does not reveal how much of each form it contains.
Mixed forms
B12 combinations
Check
Which forms are listed
Do not infer
Equal shares in a blend
More forms do not automatically establish better results.
Sublingual
Delivery method
Meaning
Under the tongue
Different from
The chemical B12 form
NIH ODS does not identify an efficacy advantage over swallowed oral B12. Choose a suitable format and follow its instructions.
Vitamin B12 dosage: RDA, %DV and high-strength products
NIH ODS lists an adult RDA of 2.4 mcg, 2.6 mcg in pregnancy and 2.8 mcg during lactation. The labeling Daily Value is 2.4 mcg. These references are distinct from a prescribed replacement dose.
Label amount
Meaning
1 mg
1,000 mcg; mcg and µg mean the same unit.
1,000 mcg
About 41,667% DV by arithmetic, not an absorbed percentage.
5,000 mcg
Five times the label amount of 1,000 mcg; not evidence of five times the benefit.
Our 100 mcg badge boundary is an editorial comparison cutoff, not an official intake or safety limit. NIH ODS reports lower fractional absorption at high doses; the label amount cannot predict an individual’s response.
B12 benefits: deficiency versus extra energy
NHLBI explains B12’s role in healthy blood cells and nerves and the consequences of deficiency. Persistent fatigue, tingling or balance problems deserve assessment; a product ranking cannot establish their cause.
Energy claims
NIH ODS finds no extra energy or endurance benefit when B12 intake is already sufficient. Correcting a deficiency is a different situation.
Which form is best?
NIH ODS finds no evidence that supplemental absorption differs by B12 form. A “methylated” or “full-spectrum” label does not by itself establish better outcomes.
Vitamin B12 evidence by goal
Evidence by goal
Goal
Evidence strength
What was assessed
Typical study context
Main limitation
Confirmed deficiency
Treatment is effective
Oral or injected B12
Cause and severity guide care
Not a retail self-diagnosis
Energy without deficiency
No established boost
Supplemental B12
Adequate baseline status
More micrograms are not more energy
Dietary coverage
Reliable B12 sources matter
Fortified foods or supplements
Especially relevant to vegan diets
Check regular intake
Neurological symptoms
Prompt assessment needed
Treatment depends on diagnosis
Severe symptoms may need injections
Do not delay care to try a brand
Read the full evidence-by-goal detail
American Family Physician’s 2025 review supports oral treatment for many patients with deficiency and consideration of injections for severe deficiency or neurological manifestations. It does not recommend universal screening. Treatment choice includes the cause, symptoms and follow-up, not just a serum number.
When and how to take B12
Follow the actual schedule
Some labels specify daily use; another may say every other day. The comparison’s daily amount can be an average. Do not change frequency because the table says “per day.”
Choose a usable format
Read whether a lozenge should dissolve, how a liquid is measured and how many gummies make one serving. This comparison does not establish a best morning or evening time.
B12 safety and symptoms needing assessment
Who should be cautious?If any of the following apply to you, speak to a healthcare professional before taking Vitamin B12 - see the full detail below for why.
New numbness, tingling, balance problems or persistent unexplained fatigue
Known malabsorption, gastrointestinal surgery or pernicious anemia
Pregnancy, breastfeeding or long-term medicines affecting B12 status
NIH ODS reports no established upper limit because B12 has low toxicity potential. That is not a reason to assume every high-dose product is necessary or every combination ingredient has the same safety profile.
NHLBI notes that neurological problems can persist even after treatment. Seek assessment for new nerve or balance symptoms rather than relying on a high-dose supplement to test the diagnosis.
B12, medicines and combination products
NIH ODS identifies metformin and acid-reducing medicines as factors that can affect B12 status. Discuss your medicine list and any need for monitoring with your clinician; do not stop prescribed treatment on your own.
Read added folate and other B-vitamin amounts separately. A “B complex” or methylation formula is not equivalent to a single-ingredient B12 product.
Older adults, vegan diets and absorption
NIH ODS advises people over 50 to obtain most B12 from fortified foods or supplements because food-bound B12 can be harder to absorb. Vegan diets need reliable fortified foods or supplements; check labels rather than assuming all plant foods supply B12.
NHLBI describes absorption problems, including pernicious anemia and gastrointestinal conditions. These require an individualized plan. An older-adult marketing label does not define a new RDA.
B12 label quality and testing
Testing review pending means the detailed product evidence review is unfinished. While testing is pending, it is excluded and the score is provisional. It does not mean a product failed testing or that no evidence exists.
FDA does not approve supplements for safety and effectiveness before sale. Check the exact product and lot behind a quality claim.
A useful report identifies the product, batch, laboratory, date, methods and results. Ingredient identity, measured content and contaminant testing answer different questions. A raw-material certificate is not automatically evidence for the bottle you buy. See how we verify testing.
Check total B12, chemical form, serving frequency and any separately disclosed blend amounts. “Active,” “methyl-free” and “no shot” describe marketing or formulation; they are not independent testing results.
B12 blood tests, pg/mL and MMA
MedlinePlus explains that vitamin testing may use blood or other samples, depending on the test. US serum B12 reports commonly use pg/mL. Give the clinician your supplement amount and timing; use the supplied laboratory interval.
Borderline values need context
The 2025 US clinical review discusses further MMA testing for borderline serum results. Cutoffs vary between methods and guidance; this page does not turn one number into a diagnosis.
What is MMA?
MedlinePlus explains methylmalonic acid testing as a way to investigate possible B12 deficiency. Kidney function and age can affect interpretation; it is not simply a score for choosing more B12.
A high result
Do not assume that higher always means healthier. Review an unexpected result with the clinician who ordered it, including supplements and the reason for testing.
Testing evidence in this comparison
A testing claim is not the same as a verified report. No public evidence located does not mean a product has not been tested.
Testing review pending0
Recognised certification3
Verified independent evidence0
Manufacturer COA1
Testing claimed12
No public evidence located4
What does vitamin b12 cost?
Current US comparison set, based on the daily serving shown on each label.
$0.05Lowest daily cost
$0.12Median daily cost
$0.75Highest daily cost
Your questions, answered
Is 1,000 mcg of B12 too much?
It is far above the RDA, but B12 has no established UL. Need and treatment are separate questions; see dose context.
