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Dietary supplement

B-12 1000 mcg Ingredients & Drug Interactions

by Foster Regal

B-12 1000 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 B-12 1000 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

B-12 1000 mcg is a dietary supplement by Foster Regal 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 B-12 1000 mcg by Foster Regal

Ask about any prescription or over-the-counter medication and we check it for interactions with B-12 1000 mcg by Foster Regal — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of B-12 1000 mcg by Foster Regal

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 12, 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 supplement contains one active ingredient: vitamin B12 at 1000 micrograms per tablet. B12 is an essential nutrient your body needs for nerve function, red blood cell formation, and DNA synthesis — your body can't make it on its own, so you have to get it from food or supplements.

The tablet also contains several inactive ingredients (calcium carbonate, vegetable cellulose, vegetable stearic acid, silica, and vegetable magnesium stearate) that help hold the tablet together and aid absorption.

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 B-12 for metabolism and energy production.
  • We looked for evidence on: Fatigue, Vitamin B12 deficiency, Peripheral neuropathy, Diabetic neuropathy, Chemotherapy-induced peripheral neuropathy, red blood cell formation — and 2 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 "Insufficient Reliable Evidence To Rate" for Chemotherapy-induced peripheral neuropathy, Diabetic neuropathy, Fatigue, Peripheral neuropathy.

B12 is established as effective for treating vitamin B12 deficiency and Imerslund-Grasbeck disease (a rare inherited condition affecting B12 absorption). It's also likely effective for cyanide poisoning.

The data shows it's possibly effective for canker sores and postherpetic neuralgia (nerve pain after shingles), though evidence for those uses is less robust.

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.

Vitamin B12 is generally very well tolerated when taken by mouth. Your body excretes excess B12 in your urine, so there's no established upper limit — you can't overdose on it from oral supplements.

The most common side effect is injection site reaction if you receive it as a shot, but oral tablets rarely cause problems. Allergic reactions like rash or itching are rare; they may occur in people with a cobalt allergy, since cobalt is part of the B12 molecule.

Very rarely, correcting severe B12 deficiency can cause a serious drop in potassium (low potassium), though this is documented only in case reports. B12 is needed in pregnancy and considered safe at normal recommended amounts — follow your provider's guidance.

It's also important during breastfeeding and considered safe at recommended amounts.

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) or similar diabetes medications, check with your pharmacist before starting — metformin can lower your B12 levels, and this supplement may help offset that, but timing and dosing matter. No other medication interactions are documented for the ingredients we checked.

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 product is a straightforward, single-ingredient B12 supplement suited for anyone with a deficiency or limited dietary intake — vegans, older adults, and people with absorption issues often benefit. If you take metformin for diabetes, mention this supplement to your pharmacist so they can keep an eye on your B12 levels.

For anyone else without that medication, B12 has no documented interactions.

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 11, 2022.

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 B-12 1000 mcg, straight from the product label.

Brand Foster Regal
Net contents 90 Tablet(s)
Market status On market
Date entered into DSLD Apr 11, 2022
DSLD ID 260136
Product type Vitamin
Supplement form Tablet Or Pill
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Women (not pregnant or lactating), Gluten 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 B-12 1000 mcg by Foster Regal, 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:
2 Tablet(s)
Servings per container
90
IngredientAmount% DV
Vitamin B121000 mcg16667%

Other ingredients: Calcium Carbonate, Vegetable Cellulose, Vegetable Stearic Acid, Silica, Vegetable Magnesium Stearate

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.
Formula

Vitamin B-12 is essential for the metabolism of carbohydrates, formulation of red blood cells and nerve tissue and for energy production.

Mfg. in a Ko Kosher Certified, FDA Registered Facility using Good Manufacturing Practices (GMPs)

Precautions

Tamper evident: Do not use this product if imprinted foil seal under cap is broken or missing.

Keep out of reach of children.

Caution: If you are pregnant or nursing, do not take this product.

Formulation

Mfg. in a Ko Kosher Certified, FDA Registered Facility using Good Manufacturing Practices (GMPs)

Timed release

Gluten free

Conforms to USP <2091> for weight.

Made in USA

Storage

Keep tightly closed. Store at room temperature: 59 degrees - 86 degrees F (15 degrees to 30 degrees C).

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Brand IP Statement(s)

Foster Regal The Best Choice.

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take 1 or 2 tablets daily.

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

See for yourself

B-12 1000 mcg by Foster Regal label

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

B-12 1000 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 B-12 1000 mcg by Foster Regal

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 Servings per container90 Amounts shown are per serving.

Vitamin B12

Interacts with
20 drugs
1000 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: Calcium Carbonate, Vegetable Cellulose, Vegetable Stearic Acid, Silica, Vegetable Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

B-12 1000 mcg by Foster Regal Drug Interactions

Want to check YOUR meds against B-12 1000 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 B-12 1000 mcg interact with 20 drugs. Click any drug to see the details.

1 of the 1 ingredient in B-12 1000 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 B-12 1000 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 B-12 1000 mcg, from the product label.

Foster Regal

See all Foster Regal products
Name
Foster Regal Laboratories
Street Address
115 S.C.T. Ct.
City
White House
State
TN
ZipCode
37188
Pharmacist Counseling Corner

B-12 1000 mcg by Foster Regal: Common Questions

Does B-12 1000 mcg by Foster Regal interact with any medications?
Yes. Based on its ingredients, B-12 1000 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?
B-12 1000 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.
Can I take this if I'm pregnant or breastfeeding?
Yes. B12 is needed in pregnancy and breastfeeding and is considered safe at normal recommended amounts. Follow your healthcare provider's advice on dosing for your individual situation.
What's the difference between this B12 and B12 shots?
Both forms work, but they get into your body differently. Oral tablets like this one are absorbed through your digestive system and work well for most people. Shots go directly into muscle or under the skin and bypass digestion entirely — your doctor might recommend shots if you have absorption problems. Injection site reactions are more common with shots than with oral tablets.
Is there an upper limit to how much B12 I can take?
No. B12 is so safe that there's no established upper limit. Any excess your body doesn't use gets filtered out in your urine, so you can't overdose on it from oral supplements.
Can I take this with metformin?
Yes, but it's worth mentioning to your pharmacist. Metformin can interfere with B12 absorption over time, so taking a B12 supplement may help — just make sure your doctor or pharmacist knows you're on both so they can monitor your B12 levels if needed.
Will this help with energy or brain fog?
B12 is effective for treating B12 deficiency, which can cause fatigue and brain problems. If low B12 is your issue, supplementing will help. If your B12 levels are normal, this supplement won't necessarily boost energy or mental clarity beyond what your body already has.

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.

B-12 1000 mcg label
Go deeper

The Full Monographs Behind B-12 1000 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

B-12 1000 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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