Interactions on record — worth a quick check against your medications. Based on 3 of 4 ingredients. Check your meds →
Dietary supplement

Methyl-Guard Ingredients & Drug Interactions

by Thorne

Methyl-Guard label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 23, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Methyl-Guard 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: Moderate

Methyl-Guard is a dietary supplement by Thorne with 4 active ingredients. Its ingredients are commonly taken for treating or preventing b12 deficiency, pernicious anemia, low energy and fatigue.Based on those ingredients, 230 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Vitamin B6, 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 Methyl-Guard by Thorne

Ask about any prescription or over-the-counter medication and we check it for interactions with Methyl-Guard by Thorne — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Methyl-Guard by Thorne

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 Aug 20, 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 4 of its 4 active ingredients.
  • “Folate” is listed as a grouped ingredient — the label gives one combined amount (2 mg DFE) without saying how much of each component you get.

Methyl-Guard contains four active ingredients. Folate is listed as a blend, with its component parts shown separately as vitamin B12, vitamin B6, and L-5-methyltetrahydrofolate — a form of folate your body uses directly.

Betaine anhydrous rounds out the formula. These work together to support methylation, a key chemical process your body runs constantly.

The capsule also contains inactive ingredients: hypromellose, silicon dioxide, calcium citrate, and calcium laurate.

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: Heart and vessel health, mood support.
  • We looked for evidence on: Cardiovascular disease (CVD), Atherosclerosis, Hyperhomocysteinemia, Hypertension, Hypertriglyceridemia, Depression — and 4 related terms.
  • The strongest evidence on file: Vitamin B6 is rated "Likely Effective" for Hyperhomocysteinemia (Natural Medicines).
  • Also on file: Vitamin B12 is rated "Possibly Effective" for Hyperhomocysteinemia.
  • Also on file: Betaine Anhydrous is rated "Possibly Effective" for Hyperhomocysteinemia.

Vitamin B12 is effective for treating B12 deficiency, Imerslund-Grasbeck disease, and cyanide poisoning. It's possibly effective for canker sores and postherpetic neuralgia (nerve pain after shingles).

Vitamin B6 is effective for sideroblastic anemia, B6 deficiency, and pyridoxine-dependent epilepsy; it's likely effective for high homocysteine levels and possibly effective for pregnancy-related nausea and vomiting. Betaine anhydrous is effective for homocystinuria and possibly effective for high homocysteine, but the evidence for nonalcoholic fatty liver disease, colorectal adenoma, depression, and GERD is insufficient.

We don't hold effectiveness data for L-5-methyltetrahydrofolate.

The evidence, ingredient by ingredient Vitamin B12 Vitamin B6 Betaine Anhydrous

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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Vitamin B12 is generally very safe — your body excretes excess in your urine, and there's no established upper limit. It's considered safe in pregnancy and breastfeeding at normal recommended amounts; follow your provider's guidance.

Vitamin B6 is safe at normal dietary and supplement amounts, but high doses over time can damage nerves (sensory neuropathy), especially doses above 1,000 mg daily or cumulative totals of 1,000 grams or more. It's likely safe in pregnancy at recommended levels, but the data shows it's possibly unsafe at higher doses; use it for morning sickness only under a doctor's supervision.

Betaine anhydrous is generally well tolerated at studied doses but causes body odor, nausea, diarrhea, and GI distress in some people. Safety in breastfeeding is not well established.

We don't have safety data on file for L-5-methyltetrahydrofolate.

Side effects, ingredient by ingredient Vitamin B12 Vitamin B6 Betaine Anhydrous

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 2 of the 3 matched ingredients can interact with medications — Vitamin B12, Vitamin B6.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: Parkinson's medications.
  • For scale: 230 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.

Before taking this product, double-check with your doctor or pharmacist if you take seizure medications (phenobarbital or phenytoin), blood pressure medications, amiodarone, metformin, or levodopa. These are the medication types with documented interactions involving vitamin B6 and vitamin B12.

Altogether, these interactions span 230 individual medications.

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. Moderate medication interactions have been identified, and safety information is well characterized.

Methyl-Guard may help if you have a B12 or B6 deficiency, high homocysteine levels, or certain forms of anemia — but check with your doctor or pharmacist first if you take seizure medications, heart rhythm drugs, blood pressure medications, metformin, or levodopa alone. The product is generally well tolerated, though betaine may cause body odor or GI upset.

Talk it over with your own healthcare provider before starting, especially if you're pregnant, breastfeeding, or on any regular medications.

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

Assessment coverage: 3 of 4 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated May 24, 2023.

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 Methyl-Guard, straight from the product label.

Brand Thorne
Barcode (UPC) 693749787037
Net contents 180 Capsule(s)
Market status On market
Date entered into DSLD May 24, 2023
DSLD ID 284244
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), 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 Methyl-Guard by Thorne, 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:
3 Capsule(s)
Maximum serving Sizes:
3 Capsule(s)
Servings per container
60
UPC/BARCODE
693749787037
IngredientAmount% DV
Folate2 mg DFE500%
Vitamin B121.2 mg50000%
Vitamin B620.4 mg1200%
L-5-Methyltetrahydrofolate1.2 mg--
Betaine Anhydrous1.8 Gram(s)--

Other ingredients: Hypromellose, Silicon Dioxide, Calcium Citrate, Calcium Laurate

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.
Formulation

Heart/Vessels Mood

Gluten free

Methylation Factors

Suggested/Recommended/Usage/Directions

Suggested use: Take 3 capsules two times daily or as recommended by your health-care practitioner.

Precautions

Tamper evident: Use only if bottle is sealed.

If pregnant, consult your health-care practitioner before using this product.

Storage

Store tightly sealed in a cool, dry place.

Seals/Symbols

Manufactured in the USA using US & imported ingredients

FDA Statement of Identity

Dietary Supplement

Formula

This product uses Gnosis S.p.A.’s L-5-Methyltetrahydrofolic Acid, Glucosamine Salt (Quatrefolic).

Brand IP Statement(s)

Quatrefolic is a registered trademark of Gnosis S.p.A.

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.

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

See for yourself

Methyl-Guard by Thorne label

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

Methyl-Guard 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 Methyl-Guard by Thorne

These are the 4 active ingredients this product is made of. Select any to open its full monograph.

Serving size3 Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Folate

2 mg DFE per serving
  • › L-5-Methyltetrahydrofolate

Vitamin B12

Interacts with
20 drugs
1.2 mg per serving Form: Methylcobalamin

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

Vitamin B6

Interacts with
210 drugs
20.4 mg per serving Form: Pyridoxal 5-Phosphate

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is b...

Vitamin B6 monograph & interactions

Betaine Anhydrous

No known
interactions
1.8 Gram(s) per serving Form: Trimethylglycine

Betaine anhydrous (also called trimethylglycine) is a compound found in foods like beets, spinach, and whole grains, and is sold as a supplement and a...

Betaine Anhydrous monograph & interactions

Other (inactive) ingredients: Hypromellose, Silicon Dioxide, Calcium Citrate, Calcium Laurate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Methyl-Guard by Thorne Drug Interactions

Want to check YOUR meds against Methyl-Guard?

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
230Drugs
205 Moderate 25 Minor

Ingredients driving the most interactions

Vitamin B6 210
Vitamin B12 20

Individual Drug Interactions

The ingredients in Methyl-Guard interact with 230 drugs. Click any drug to see the details.

2 of the 4 ingredients in Methyl-Guard interact with drugs. Each result below shows which ingredient is responsible. Vitamin B6 Vitamin B12

Each ingredient & the kinds of drugs it affects

For each ingredient in Methyl-Guard with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Vitamin B65 drug types · 210 drugs

Amiodarone (Cordarone)

Theoretically, vitamin B6 might increase the photosensitivity caused by amiodarone.
Despite initial case reports suggesting that pyridoxine may have a protective effect against amiodarone-induced photosensitivity, preliminary clinical research suggests that pyridoxine may actually exacerbate this adverse effect.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, vitamin B6 may have additive effects when used with antihypertensive drugs.
Research in hypertensive rats shows that vitamin B6 can decrease systolic blood pressure. Similarly, clinical research in patients with hypertension shows that taking high doses of vitamin B6 may reduce systolic and diastolic blood pressure, possibly by reducing plasma levels of epinephrine and norepinephrine.

Likelihood Possible Evidence B
Phenobarbital (Luminal)

High doses of vitamin B6 may reduce the levels and clinical effects of phenobarbital.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenobarbital, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenobarbital to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Phenytoin (Dilantin)

High doses of vitamin B6 may reduce the levels and clinical effects of phenytoin.
Preliminary clinical evidence suggests that vitamin B6 200 mg daily can reduce plasma levels of phenytoin, possibly by increasing metabolism. It is not known whether lower doses have any effect. Advise people taking phenytoin to avoid high doses of vitamin B6.

Likelihood Possible Evidence D
Levodopa

Vitamin B6 may increase the metabolism of levodopa when taken alone, but not when taken in conjunction with carbidopa.
Vitamin B6 (pyridoxine) enhances the metabolism of levodopa, reducing its clinical effects. However, this interaction does not occur when carbidopa is used concurrently with levodopa (Sinemet). Therefore, it is not likely to be a problem in most people.

Likelihood Unlikely Evidence D
Vitamin B6 full monograph & interactions

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 Methyl-Guard, from the product label.

Thorne

See all Thorne products
Name
Thorne Research, Inc.
Phone Number
1-800-228-1966
Pharmacist Counseling Corner

Methyl-Guard by Thorne: Common Questions

Does Methyl-Guard by Thorne interact with any medications?
Yes. Based on its ingredients, Methyl-Guard has a known interaction with 230 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Methyl-Guard contains 4 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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.
Is it safe to take Methyl-Guard while I'm pregnant?
Vitamin B12 is considered safe during pregnancy at normal recommended amounts. Vitamin B6 is likely safe at recommended levels and is often used for morning sickness, but only under a doctor's guidance — the data shows it may be unsafe at higher doses. We don't have pregnancy safety data for L-5-methyltetrahydrofolate or betaine anhydrous. Talk with your doctor or pharmacist before starting, as any supplement in pregnancy deserves personalized advice.
Can I take this while breastfeeding?
Vitamin B12 is considered safe during breastfeeding at recommended amounts. Vitamin B6 is likely safe at those levels too. Betaine anhydrous safety while breastfeeding is not well established, so caution is advised. Check with your doctor or pharmacist about the best choice for you and your baby.
What is L-5-methyltetrahydrofolate, and why is it in this formula?
L-5-methyltetrahydrofolate is an active form of folate — your body can use it directly without converting it first, which makes it useful for certain people. We don't hold data on its interactions or side effects, so if you have questions about it specifically, ask your pharmacist.
Why does the label say Folate but then list other forms?
Folate on the label indicates a blend or combination of different folate forms, which are then listed individually: vitamin B12, vitamin B6, and L-5-methyltetrahydrofolate. This gives you multiple forms of B vitamins to support methylation in your body.
Will this product cause side effects?
Vitamin B12 and B6 are well tolerated at normal doses. Betaine anhydrous may cause body odor, nausea, diarrhea, or GI distress in some people. High doses of vitamin B6 over time (above 1,000 mg daily) can damage nerves. If you notice any unusual symptoms after starting, tell your doctor or pharmacist.
Is this safe if I take metformin for diabetes?
Metformin can lower your B12 levels over time by interfering with absorption in your digestive system. Taking a B12 supplement may help offset this, but let your doctor or pharmacist know you're considering it so they can monitor your levels or adjust your care as needed.

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.

Methyl-Guard label
Go deeper

The Full Monographs Behind Methyl-Guard’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 → Herb & supplement monograph

Vitamin B6

Interacts with 210 drugs

Vitamin B6 (pyridoxine) is an essential water-soluble vitamin that your body needs for metabolism, brain function, and making red blood cells. It is best known for helping with pregnancy-rel...

Read the full Vitamin B6 monograph → Herb & supplement monograph

Betaine Anhydrous

Betaine anhydrous (also called trimethylglycine) is a compound found in foods like beets, spinach, and whole grains, and is sold as a supplement and as a prescription medicine for a rare gen...

Read the full Betaine Anhydrous monograph →
Sources

Sources & How We Checked

Methyl-Guard'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 73 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 →

Vitamin B6 32 references
  1. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  2. Yates AA, Schlicker SA, Suitor CW. Dietary reference intakes: The new basis for recommendations for calcium and related nutrients, B vitamins, and choline. J Am Diet Assoc 1998;98:699-706. PubMed
  3. Geerling BJ, Dagnelie PC, Badart-Smook A, et al. Diet as a risk factor for the development of ulcerative colitis. Am J Gastroenterol 2000;95:1008-13. PubMed
  4. South M. Neonatal seizures after pyridoxine use -- reply. Lancet 1999;354:2083. PubMed
  5. 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
  6. Baxter P, Aicardi J. Neonatal seizures after pyridoxine use. Lancet 1999;354:2082-3. PubMed
  7. Bendich A, Cohen M. Vitamin B6 safety issues. Ann N Y Acad Sci 1990;585:321-30.
  8. Schaumburg H, Kaplan J, Windebank A. Sensory neuropathy from pyridoxine abuse. A new megavitamin syndrome. N Engl J Med 1983;309:445-8. PubMed
  9. Gordon N. Pyridoxine dependency: an update. Dev Med Child Neurol 1997;39:63-5. PubMed
  10. Lewis PJ. Pain in the hand and wrist. Pyridoxine supplements may help patients with carpal tunnel syndrome. BMJ 1995;310:1534. PubMed
  11. Kaufman G. Pyridoxine against amiodarone-induced photosensitivity (letter). Lancet 1984;1:51-2. PubMed
  12. Mulrow JP, Mulrow CD, McKenna WJ. Pyridoxine and amiodarone-induced photosensitivity. Ann Intern Med 1985;103:68-9. PubMed
  13. Kawada A, Kashima A, Shiraishi H, et al. Pyridoxine-induced photosensitivity and hypophosphatasia. Dermatology 2000;201:356-60.. PubMed
  14. Vasile A, Goldberg R, Kornberg B. Pyridoxine toxicity: report of a case. J Am Osteopath Assoc 1984;83:790-1. DOI
  15. Hansson O, Sillanpaa M. Pyridoxine and serum concentration of phenytoin and phenobarbitone. Lancet 1976;1:256. DOI
  16. 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..
  17. Chittumma P, Kaewkiattikun K, Wiriyasiriwach B. Comparison of the effectiveness of ginger and vitamin B6 for treatment of nausea and vomiting in early pregnancy: a randomized double-blind controlled trial. J Med Assoc Thai 2007;90:15-20.
  18. Hatzitolios, A., Iliadis, F., Katsiki, N., and Baltatzi, M. Is the anti-hypertensive effect of dietary supplements via aldehydes reduction evidence based? A systematic review. Clin Exp.Hypertens. 2008;30(7):628-639. PubMed
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  21. Hagen, I., Nesheim, B. I., and Tuntland, T. No effect of vitamin B-6 against premenstrual tension. A controlled clinical study. Acta Obstet.Gynecol.Scand. 1985;64(8):667-670. PubMed
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  23. Lal, K. J., Dakshinamurti, K., and Thliveris, J. The effect of vitamin B6 on the systolic blood pressure of rats in various animal models of hypertension. J Hypertens. 1996;14(3):355-363. PubMed
  24. Lauritzen CH, Reuter HD, Repges R, Bohnert K, and Schmidt U. Treatment of premenstrual tension syndrome with Vitex agnus castus. Controlled, double-blind study versus pyridoxine. Phytomed 1997;4(3):183-189. PubMed
  25. Fonseca VA, Lavery LA, Thethi TK, et al. Metanx in type 2 diabetes with peripheral neuropathy: A randomized trial. Am J Med 2013;126(2):141-9. PubMed
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  28. Mahmoud A, Tabassum S, Al Enazi S, et al. Amelioration of levetiracetam-induced behavioral side effects by pyridoxine. A randomized double blind controlled study. Pediatr Neurol 2021;119:15-21. PubMed
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See these in context on the Vitamin B6 monograph →

Betaine Anhydrous 11 references
  1. Cystadane (betaine anhydrous for oral solution) Package insert. Orphan Medical, Inc. Minnetonka, MN. November 2005.
  2. Abdelmalek MF, Angulo P, Jorgensen RA, et al. Betaine, a promising new agent for patients with nonalcoholic steatohepatitis: results of a pilot study. Am J Gastroenterol 2001;96:2711-7.. PubMed
  3. Schwab U, Torronen A, Toppinen L, et al. Betaine supplementation decreases plasma homocysteine concentrations but does not affect body weight, body composition, or resting energy expenditure in human subjects. Am J Clin Nutr 2002;76:961-7. PubMed
  4. McGregor DO, Dellow WJ, Robson RA, et al. Betaine supplementation decreases post-methionine hyperhomocysteinemia in chronic renal failure. Kidney Int 2002;61:1040-6. PubMed
  5. Olthof MR, van Vliet T, Verhoef P, et al. Effect of homocysteine-lowering nutrients on blood lipids: results from four randomised, placebo-controlled studies in healthy humans. PloS Med 2005;2:e135. PubMed
  6. Knopman, D. and Patterson, M. An open-label, 24-week pilot study of the methyl donor betaine in Alzheimer disease patients. Alzheimer Dis.Assoc.Disord. 2001;15(3):162-165. PubMed
  7. Moat, S. J., Madhavan, A., Taylor, S. Y., Payne, N., Allen, R. H., Stabler, S. P., Goodfellow, J., McDowell, I. F., Lewis, M. J., and Lang, D. High- but not low-dose folic acid improves endothelial function in coronary artery disease. Eur J Clin Invest 2 PubMed
  8. Abdelmalek, M. F., Sanderson, S. O., Angulo, P., Soldevila-Pico, C., Liu, C., Peter, J., Keach, J., Cave, M., Chen, T., McClain, C. J., and Lindor, K. D. Betaine for nonalcoholic fatty liver disease: results of a randomized placebo-controlled trial. Hepa PubMed
  9. Ashtary-Larky D, Bagheri R, Ghanavati M, et al. Effects of betaine supplementation on cardiovascular markers: a systematic review and meta-analysis. Crit Rev Food Sci Nutr. 2021 Mar 25:1-18. PubMed
  10. Zawieja EE, Zawieja B, Chmurzynska A. Betaine supplementation moderately increases total cholesterol levels: a systematic review and meta-analysis. J Diet Suppl. 2021;18(1):105-117. PubMed
  11. Imbard A, Toumazi A, Magréault S, et al. Efficacy and pharmacokinetics of betaine in CBS and cblC deficiencies: a cross-over randomized controlled trial. Orphanet J Rare Dis 2022;17(1):417. PubMed

See these in context on the Betaine Anhydrous monograph →

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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.

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