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Dietary supplement

Vitamin B-12 500 mcg Ingredients & Drug Interactions

by Rugby

Vitamin B-12 500 mcg label
See full label image
Tablet Or Pill Category: Vitamin
Most serious interaction: Minor
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Vitamin B-12 500 mcg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Minor

Vitamin B-12 500 mcg is a dietary supplement by Rugby with 1 active ingredient. Its ingredients are commonly taken for treating or preventing b12 deficiency, pernicious anemia, low energy and fatigue.Based on those ingredients, 20 medications have a known interaction with it, the most serious rated minor. The ingredients most likely to interact are Vitamin B12. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Vitamin B-12 500 mcg by Rugby

Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin B-12 500 mcg by Rugby — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Vitamin B-12 500 mcg by Rugby

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: vitamin B-12 (cyanocobalamin), 500 mcg per tablet. B-12 is an essential nutrient your body uses for nerve function, DNA, and red blood cell formation.

The tablet also includes inactive ingredients — microcrystalline cellulose, croscarmellose sodium, magnesium stearate, stearic acid, and FD&C Yellow #5 Aluminum Lake — which are fillers and binders that hold the tablet together.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: Vitamin B12 supplement.
  • We looked for evidence on: Vitamin B12 deficiency, Fatigue, Peripheral neuropathy, Diabetic neuropathy, Chemotherapy-induced peripheral neuropathy, Hyperhomocysteinemia — and 3 related terms.
  • The strongest evidence on file: Vitamin B12 is rated "Effective" for Vitamin B12 deficiency (Natural Medicines).
  • Also on file: Vitamin B12 is rated "Possibly Effective" for Hyperhomocysteinemia.
  • Also on file: Vitamin B12 is rated "Insufficient Reliable Evidence To Rate" for Chemotherapy-induced peripheral neuropathy, Diabetic neuropathy, Fatigue, Peripheral neuropathy.

Vitamin B-12 is effective for treating B-12 deficiency itself and for Imerslund-Grasbeck disease, a rare inherited condition affecting B-12 absorption. It's also likely effective for cyanide poisoning.

For canker sores and postherpetic neuralgia (nerve pain after shingles), the evidence is possibly effective — meaning there's some support, but it's not as strong. If you're taking B-12 for one of those last two uses, talk with your pharmacist about what the research shows.

The evidence, ingredient by ingredient Vitamin B12

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

B-12 is generally very well tolerated by mouth. Your body excretes excess B-12 in your urine, so there's no established upper limit — you can't really overdose on it.

Oral B-12 is considered safe during pregnancy and breastfeeding at recommended amounts; follow your provider's guidance on dosing. Side effects are rare.

Most people have none. Very rarely, allergic reactions like rash or itching can occur — in one case, someone with a cobalt allergy developed a rash from oral B-12 supplements.

Serious side effects like severe low potassium (hypokalemia) are extremely rare and tied to correction of certain anemias, not routine supplementation.

Side effects, ingredient by ingredient Vitamin B12

Meds to double-check

Minor interactions only
Known Interaction Concern · database check
Minor only

Only Minor-severity interactions are documented for these ingredients.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Vitamin B12.
  • The most serious interaction on file is rated Minor.
  • For scale: 20 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

If you take metformin (Glucophage) for diabetes, check in with your pharmacist before starting — metformin can lower B-12 levels. For any other prescription medications, run them through the search tool below to be sure.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Only minor medication interactions are documented, and safety information is well characterized.

This is a straightforward B-12 supplement for anyone with a deficiency or at risk for one — including vegetarians, older adults, and people taking metformin long-term. If you're on metformin, definitely mention this supplement to your doctor or pharmacist so they can keep an eye on your B-12 levels.

It's safe, well tolerated, and your body will use what it needs and discard the rest.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Apr 25, 2019.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Vitamin B-12 500 mcg, straight from the product label.

Brand Rugby
Barcode (UPC) 005363551015
Net contents 100 Tablet(s)
Market status On market
Date entered into DSLD Apr 25, 2019
DSLD ID 201265
Product type Vitamin
Supplement form Tablet Or Pill
Dietary claims / uses All Other
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Vitamin B-12 500 mcg by Rugby, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Tablet(s)
Maximum serving Sizes:
1 Tablet(s)
UPC/BARCODE
005363551015
IngredientAmount% DV
Vitamin B12500 mcg8333%

Other ingredients: Microcrystalline Cellulose, Croscarmellose Sodium, Magnesium Stearate, Stearic Acid, FD&C Yellow #5 Aluminum Lake

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

New formula and appearance

Made in Canada MP 979-05

FDA Statement of Identity

Dietary Supplement

Precautions

Tamper resistant - Do not use if safety seal is broken or missing.

Warning: If you are pregnant, nursing, taking any medications or planning any medical procedure, consult your doctor before use.

Discontinue use and consult your doctor if any adverse reactions occur.

Keep out of reach of children.

Suggested/Recommended/Usage/Directions

Directions: Adults: As a dietary supplement, take one tablet daily, preferably with a meal, or as directed by a health care professional.

Formulation

Free of: Sugar, sodium, starch, wheat, corn, gluten, yeast, soy, egg, fragrance, artificial flavors and preservatives.

Storage

Keep bottle tightly closed. Store between 15(0)- 30(0)C (59(0)- 86(0)F).

General

Rev. 05/17 R-147 Re-order No. 370546

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Vitamin B-12 500 mcg by Rugby label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Vitamin B-12 500 mcg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Vitamin B-12 500 mcg by Rugby

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Tablet(s) Dosage formTablet Or Pill Amounts shown are per serving.

Vitamin B12

Interacts with
20 drugs
500 mcg per serving Form: Cyanocobalamin

Vitamin B12 (cobalamin) is an essential nutrient your body needs to make red blood cells, keep nerves healthy, and support DNA. Supplements are very h...

Vitamin B12 monograph & interactions

Other (inactive) ingredients: Microcrystalline Cellulose, Croscarmellose Sodium, Magnesium Stearate, Stearic Acid, FD&C Yellow #5 Aluminum Lake. These complete the product’s ingredient list but are not active constituents.

Interaction report

Vitamin B-12 500 mcg by Rugby Drug Interactions

Want to check YOUR meds against Vitamin B-12 500 mcg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
20Drugs
20 Minor

Ingredients driving the most interactions

Vitamin B12 20

Individual Drug Interactions

The ingredients in Vitamin B-12 500 mcg interact with 20 drugs. Click any drug to see the details.

1 of the 1 ingredient in Vitamin B-12 500 mcg interact with drugs. Each result below shows which ingredient is responsible. Vitamin B12

Each ingredient & the kinds of drugs it affects

For each ingredient in Vitamin B-12 500 mcg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Vitamin B121 drug type · 20 drugs

Metformin (Glucophage)

Metformin, a common medication used to manage type 2 diabetes, has been associated with lower vitamin B12 levels in some individuals. Prolonged use of metformin can interfere with the absorption of B12 in the digestive system, potentially leading to a deficiency in this essential vitamin.

Likelihood Possible Evidence A
Vitamin B12 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Vitamin B-12 500 mcg, from the product label.

Rugby

See all Rugby products
Name
Rugby Laboratories
Street Address
17177 N Laurel Park Drive, Suite 233
City
Livonia
State
MI
ZipCode
48152
Phone Number
1-800-645-2158
Web Address
www.rugbylaboratories.com
Pharmacist Counseling Corner

Vitamin B-12 500 mcg by Rugby: Common Questions

Does Vitamin B-12 500 mcg by Rugby interact with any medications?
Yes. Based on its ingredients, Vitamin B-12 500 mcg has a known interaction with 20 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Vitamin B-12 500 mcg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Will this help if I'm taking metformin?
Metformin can interfere with B-12 absorption over time, potentially leading to a deficiency. This supplement may help, but it's a Minor interaction — talk with your doctor or pharmacist about monitoring your B-12 levels and the right dose for you.
Is B-12 safe to take while pregnant or breastfeeding?
Yes. B-12 is actually needed during pregnancy and breastfeeding, and it's considered safe at recommended amounts. Follow your provider's advice on dosing during these times.
Can I overdose on B-12?
No. Your body excretes excess B-12 in urine, so there's no established upper limit. You can't really take too much.
What are the side effects?
B-12 is generally well tolerated by mouth, and side effects are rare. Very rarely, allergic reactions like rash or itching can happen — especially if you have a cobalt allergy. Serious side effects are extremely uncommon with oral supplements.
Does this treat canker sores or nerve pain?
B-12 is possibly effective for both canker sores and postherpetic neuralgia (nerve pain after shingles), meaning there's some evidence but it's not as strong as for B-12 deficiency itself. Talk with your pharmacist about whether it's right for your situation.
How much B-12 do I need?
That depends on your age, diet, and health status. Your doctor or pharmacist can help you figure out the right dose — especially if you're vegetarian, over 50, or taking metformin long-term.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Vitamin B-12 500 mcg label
Go deeper

The Full Monographs Behind Vitamin B-12 500 mcg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Vitamin B12

Interacts with 20 drugs

Vitamin B12 (cobalamin) is an essential nutrient your body needs to make red blood cells, keep nerves healthy, and support DNA. Supplements are very helpful for people who are deficient — su...

Read the full Vitamin B12 monograph →
Sources

Sources & How We Checked

Vitamin B-12 500 mcg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 30 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Vitamin B12 30 references
  1. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
  2. Hartman TJ, Woodson K, Stolzenberg-Solomon R, et al. Association of the B-vitamins pyridoxal 5'-phosphate (B6), B12, and folate with lung cancer risk in older men. Am J Epidemiol 2001;153:688-94.. DOI
  3. Jansen T, Romiti R, Kreuter A, Altmeyer P. Rosacea fulminans triggered by high-dose vitamins B6 and B12. J Eur Acad Dermatol Venereol 2001;15:484-5..
  4. Lange H, Suryapranata H, De Luca G, et al. Folate therapy and in-stent restenosis after coronary stenting. N Engl J Med 2004;350:2673-81. PubMed
  5. Collin, S. M., Metcalfe, C., Refsum, H., Lewis, S. J., Zuccolo, L., Smith, G. D., Chen, L., Harris, R., Davis, M., Marsden, G., Johnston, C., Lane, J. A., Ebbing, M., Bonaa, K. H., Nygard, O., Ueland, P. M., Grau, M. V., Baron, J. A., Donovan, J. L., Nea
  6. Geissbuhler, P., Mermillod, B., and Rapin, C. H. Elevated serum vitamin B12 levels associated with CRP as a predictive factor of mortality in palliative care cancer patients: a prospective study over five years. J.Pain Symptom.Manage. 2000;20(2):93-103. PubMed
  7. Salles, N., Herrmann, F., Sakbani, K., Rapin, C. H., and Sieber, C. High vitamin B12 level: a strong predictor of mortality in elderly inpatients. J Am Geriatr.Soc 2005;53(5):917-918.
  8. Looker, H. C., Fagot-Campagna, A., Gunter, E. W., Pfeiffer, C. M., Sievers, M. L., Bennett, P. H., Nelson, R. G., Hanson, R. L., and Knowler, W. C. Homocysteine and vitamin B(12) concentrations and mortality rates in type 2 diabetes. Diabetes Metab Res R
  9. Uhl, W., Nolting, A., Golor, G., Rost, K. L., and Kovar, A. Safety of hydroxocobalamin in healthy volunteers in a randomized, placebo-controlled study. Clin Toxicol (Phila) 2006;44 Suppl 1:17-28. PubMed
  10. Borron, S. W., Baud, F. J., Barriot, P., Imbert, M., and Bismuth, C. Prospective study of hydroxocobalamin for acute cyanide poisoning in smoke inhalation. Ann Emerg.Med 2007;49(6):794-801, 801. PubMed
  11. Borron, S. W., Baud, F. J., Megarbane, B., and Bismuth, C. Hydroxocobalamin for severe acute cyanide poisoning by ingestion or inhalation. Am J Emerg.Med 2007;25(5):551-558. PubMed
  12. Lewis, J. G. Gout, Steatorrhoea, and Megaloblastic Anaemia. Ann Rheum.Dis 1962;21(3):284-286. PubMed
  13. Tal, S., Shavit, Y., Stern, F., and Malnick, S. Association between vitamin B12 levels and mortality in hospitalized older adults. J Am Geriatr.Soc 2010;58(3):523-526. PubMed
  14. Baztan, J. J., Gavidia, J. J., Gomez-Pavon, J., Esteve, A., and Ruiperez, I. High vitamin B12 levels and in-hospital mortality. J Am Geriatr.Soc 2010;58(11):2237-2238. PubMed
  15. Omboni, E., Checchini, M., and Longoni, F. [Hypopotassemia and megaloblastic anemia. Presentation of a case]. Minerva Med 8-31-1987;78(16):1255-1257.
  16. Aalfs As, Scholvinck LH, Horvath B. Acneiform eruption in a 5-year old due to vitamin B12 supplementation. Eur J Dermatol 2013;23(5):726-7. PubMed
  17. Balta I, Ozuguz P. Vitamin B12-induced acneiform eruption. Cutan Ocul Toxicol 2014;33(2):94-5. PubMed
  18. Carman KB, Belgemen T, Yis U. Involuntary movements misdiagnosed as seizure during vitamin B12 treatment. Pediatr Emerg Care 2013;29(11):1223-4. PubMed
  19. Djuric V, Bogic M, Popadic AP, et al. Anaphylactic reaction to hydroxycobalamin with tolerance to cyanocobalamin. Ann Allergy Asthma Immunol 2012;108(3):207-8. PubMed
  20. Kartel O, Gulec M, Demirel F, et al. Vitamin B12 allergy and successful desensitization with cyanocobalamin: A case report. Allergol Immunopath (Madr) 2012;40(5):324-5.
  21. Patiroglu T, Unal E, Yildirim S. Infantile tremor syndrome associated with cobalamin therapy: A case report. Clin Neurol Neurosurg 2013;115(9):1903-5. PubMed
  22. Schulte S, Barkema LW, Kardaun SH. Long-lasting atypical acneiform eruption with prominent comedones induced by hydroxocobalamin (vitamin B12). J Dtsch Dermatol Ges 2014;12(6):502-3.
  23. Zanus C, Alberini E, Costa P, et al. Involuntary movements after correction of vitamin B12 deficiency: A video-case report. Epileptic Disord 2012;14(2):174-80. PubMed
  24. Fanidi A, Carreras-Torres R, Larose TL, et al. Is high vitamin B12 status a cause of lung cancer? Int J Cancer. 2019 Sep 15;145(6):1499-1503. PubMed
  25. Fujita Y, Mizukami T, Maya Y, et al. Vitamin B12 allergy manifesting as lymphomatoid contact dermatitis. Eur J Dermatol. 2020;30(3):304-305. PubMed
  26. Dépret F, Hoffmann C, Daoud L, et al. Association between hydroxocobalamin administration and acute kidney injury after smoke inhalation: a multicenter retrospective study. Crit Care. 2019;23(1):421. PubMed
  27. Khairan P, Sobue T, Eshak ES, et al. Association of dietary intakes of vitamin B12, vitamin B6, folate, and methionine with the risk of esophageal cancer: the Japan Public Health Center-based (JPHC) prospective study. BMC Cancer 2021;21(1):982. PubMed
  28. Evans J, Pandya A, Ding Y, Qunibi WY. Hydroxocobalamin-Induced Oxalate Nephropathy in a Patient With Smoke Inhalation. Kidney Int Rep 2021;6(8):2228-2231. PubMed
  29. Lacombe V, Chabrun F, Lacout C, et al. Persistent elevation of plasma vitamin B12 is strongly associated with solid cancer. Sci Rep 2021;11(1):13361. PubMed
  30. Pegalajar-García MD, Cebolla-Verdugo M, Prados-Carmona Á, Llamas-Segura C, Navarro-Triviño FJ. Systemic allergic dermatitis to cobalt present in cyanocobalamin supplementation. Contact Dermatitis 2023;89(3):203-205. PubMed

See these in context on the Vitamin B12 monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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