Interactions on record — worth a quick check against your medications. Based on 4 of 5 ingredients. Check your meds →
Dietary supplement

Grey + Defence Xtreme 2.0 Ingredients & Drug Interactions

by COORGA Nutraceuticals

Grey + Defence Xtreme 2.0 label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Grey + Defence Xtreme 2.0 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

Grey + Defence Xtreme 2.0 is a dietary supplement by COORGA Nutraceuticals with 5 active ingredients. Its ingredients are commonly taken for morning sickness in pregnancy, premenstrual syndrome (pms), preventing or treating b6 deficiency.Based on those ingredients, 525 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Selenium, Vitamin B6, Folic Acid. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Grey + Defence Xtreme 2.0 by COORGA Nutraceuticals

Ask about any prescription or over-the-counter medication and we check it for interactions with Grey + Defence Xtreme 2.0 by COORGA Nutraceuticals — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Grey + Defence Xtreme 2.0 by COORGA Nutraceuticals

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 5 of its 5 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Grey + Defence Xtreme 2.0 has 5 active ingredients. Vitamin B6, folic acid, and vitamin B12 are B vitamins that support energy and nervous system function.

Selenium is a mineral that acts as an antioxidant. The fifth ingredient, GD Gris Verso, is included but we have no data on file about it.

The capsule also contains inactive ingredients — glycerin, water, hypromellose, titanium dioxide, and an enteric coating — which help deliver and protect the formula.

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: Grey hair support and antioxidant immune health.
  • We looked for evidence on: Anemia, Hair pigmentation, Hair graying, Antioxidant defense, General wellness.
  • The strongest evidence on file: Vitamin B6 is rated "Effective" for Sideroblastic anemia (Natural Medicines).
  • Also on file: Folic Acid is rated "Possibly Ineffective" for Anemia.

Vitamin B6 is effective for sideroblastic anemia and B6 deficiency, and likely effective for lowering homocysteine. It's possibly effective for pregnancy-related nausea.

Folic acid is effective for folate deficiency and likely effective for preventing neural tube birth defects and treating methotrexate side effects; it's possibly effective for depression and cognitive issues. Vitamin B12 is effective for B12 deficiency and a rare disease called Imerslund-Grasbeck disease, and likely effective for cyanide poisoning.

It's possibly effective for canker sores and nerve pain after shingles. Selenium is likely effective for selenium deficiency and possibly effective for certain thyroid and pregnancy conditions, but the evidence we hold rates it as possibly ineffective for high cholesterol.

The evidence, ingredient by ingredient Vitamin B6 Folic Acid Vitamin B12 Selenium

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 4 of the 4 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 4 of 4.
  • General safety write-ups exist for 4 of 4.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Vitamin B6 is well tolerated at doses under 100 mg daily, but high doses over time can damage nerves (sensory neuropathy), especially at 1,000 mg daily or more. Common side effects at any dose include headache, nausea, and heartburn.

Folic acid is generally safe at recommended amounts; pregnant women are advised to take it at standard prenatal doses to prevent birth defects, and it's safe while breastfeeding. High doses (15 mg daily) can cause sleep problems, confusion, and irritability.

Vitamin B12 is very safe with no established upper limit because excess is removed in urine; it's needed in pregnancy and breastfeeding at normal recommended amounts. Selenium is safe within the tolerable upper limit of 400 mcg daily, but excess can be toxic, causing hair loss, nail problems, fatigue, and in severe cases organ damage.

GD Gris Verso has no safety data on file.

Side effects, ingredient by ingredient Vitamin B6 Folic Acid Vitamin B12 Selenium

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?
  • 4 of the 4 matched ingredients can interact with medications — Vitamin B12, Vitamin B6, Selenium, Folic Acid.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; Parkinson's medications.
  • For scale: 525 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.

Check your medications against this product if you take seizure drugs (phenobarbital, phenytoin, or primidone), blood thinners or antiplatelet drugs (including warfarin), cancer medications (methotrexate, capecitabine, 5-fluorouracil), diabetes medicine (metformin), or medications that suppress the immune system. These carry Moderate interactions.

Also check if you take barbiturates (sedating drugs used for sleep or anxiety), pyrimethamine (for parasites), oral contraceptives, or niacin — these have Minor interactions.

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.

This product may be useful if you have a B vitamin or selenium deficiency, but it carries real risks if you take seizure medications, certain cancer drugs, blood thinners, or diabetes medication. Talk to your pharmacist or doctor before starting, especially if you take any prescription medicine — the medication checker on this page will help you look up your exact drugs.

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

Assessment coverage: 4 of 5 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 26, 2014.

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 Grey + Defence Xtreme 2.0, straight from the product label.

Brand COORGA Nutraceuticals
Barcode (UPC) 869430000000
Net contents 30 Capsule(s)
Market status On market
Date entered into DSLD Aug 26, 2014
DSLD ID 36447
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 Grey + Defence Xtreme 2.0 by COORGA Nutraceuticals, 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 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
30
UPC/BARCODE
869430000000
IngredientAmount% DV
Vitamin B610 mg500%
Folic Acid300 mcg75%
Vitamin B121000 mcg1667%
Selenium180 mcg257%
GD Gris Verso247.69 mg--

Other ingredients: Glycerin, Water, Hypromellose, Titanium Dioxide, Enteric coating

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

GD Gris Verso is an enzyme preparation containing Astragalus membranaceus root extract extract, Panax Notoginseng leaf extract, Catalase , Pterostilbene and L-Methionine.

Contains 84,000 Catalase enzyme units (2,100 Baker Units) per capsule

Formulation

Not a signicant source of Calories, Cholesterol, Fat, Fiber, Iron, Protein, Sodium, Sugars, Vitamin A and Vitamin C. Does not contain animal by-products.

Phthalates Free!

Gluten Free!

Seals/Symbols

Grey+ Defense

VEGETARIAN LIQUID FILLED CAPSULES Enteric Coated

General Statements

Made in USA (contains imported materials)

NEW

The Grey Hair Fighter!

Provides Antioxidants! Supports Immune Health!

PATENT PROTECTED

By purchasing this product you agree to be bound by our refund policy in effect at the time of purchase for all damages including but not limited to direct, consequential, special, incidental and indirect damages, where such limitations are allowable by law.

The body’s anti-oxidative defensive network includes antioxidant enzymes Catalase and Glutathione Peroxidase that efficiently neutralizes hydrogen peroxide when we are young.

Grey Defence(R) was formulated to re-energize this natural grey hair defence system.

This product was manufactured in a GMP facility.

FDA Statement of Identity

DIETARY/FOOD SUPPLEMENT

Brand IP Statement(s)

Grey Defence(R) does not work for all greying types and may not produce the results you desire; before purchasing please review our website FAQ to understand the product’s limitations.

Suggested/Recommended/Usage/Directions

Recommended Use: As a vitamin/mineral supplement to help fight against greying due to hydrogen peroxide bleaching. For adults who started greying after age 30 and who have been greying for less than 7 years (e.g., 52 year old who started greying at age 45). Take 1 capsule in the morning on empty stomach. Wait 45 minutes before consuming solid meal. Recommended for continuous usage of at least 6 to 18 months.

Precautions

CAUTION Do not exceed recommended dose.

Pregnant or nursing mothers, children under 18 and individuals with a known medical condition should consult a physician before using this or any dietary supplement.

Pregnant or nursing mothers, children under 18 and individuals with a known medical condition should consult a physician before using this or any dietary supplement.

Keep out of reach of children.

Do not use if safety seal is damaged or missing.

Do not take with multivitamins containing more than 200mcg Selenium daily dosage. If you have an auto-immune disorder, consult a health care practitioner prior to use.

Hypersensitivity/allergy has been known to occur; in which case, discontinue use.

For prolonged use, consult a health care practitioner. Some people may experience an increase in appetite.

Storage

Store in a cool dry place.

FDA Disclaimer Statement

DISCLAIMER: By law the Food and Drug Administration does not pre-approve dietary supplements; therefore the preceding statements have not been evaluated by the FDA.

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

See for yourself

Grey + Defence Xtreme 2.0 by COORGA Nutraceuticals label

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

Grey + Defence Xtreme 2.0 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 Grey + Defence Xtreme 2.0 by COORGA Nutraceuticals

These are the 5 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container30 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.

Vitamin B6

Interacts with
210 drugs
10 mg per serving Form: Pyridoxine Hydrochloride

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

Folic Acid

Interacts with
40 drugs
300 mcg per serving

Folic acid is the man-made form of vitamin B9 and is one of the most well-studied supplements, especially for preventing serious birth defects when ta...

Folic Acid monograph & interactions

Vitamin B12

Interacts with
20 drugs
1000 mcg 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

Selenium

Interacts with
321 drugs
180 mcg per serving Form: Selenium Amino Acid Chelate

Selenium is an essential trace mineral your body needs in small amounts for thyroid function, antioxidant defense, and immune health. Most people who...

Selenium monograph & interactions

GD Gris Verso

247.69 mg per serving

Other (inactive) ingredients: Glycerin, Water, Hypromellose, Titanium Dioxide, Enteric coating. These complete the product’s ingredient list but are not active constituents.

Interaction report

Grey + Defence Xtreme 2.0 by COORGA Nutraceuticals Drug Interactions

Want to check YOUR meds against Grey + Defence Xtreme 2.0?

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
525Drugs
467 Moderate 58 Minor

Ingredients driving the most interactions

Selenium 321
Vitamin B6 210
Folic Acid 40
Vitamin B12 20

Individual Drug Interactions

The ingredients in Grey + Defence Xtreme 2.0 interact with 525 drugs. Click any drug to see the details.

4 of the 5 ingredients in Grey + Defence Xtreme 2.0 interact with drugs. Each result below shows which ingredient is responsible. Selenium Vitamin B6 Folic Acid Vitamin B12

Each ingredient & the kinds of drugs it affects

For each ingredient in Grey + Defence Xtreme 2.0 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.

Selenium6 drug types · 321 drugs

Anticoagulant/Antiplatelet Drugs

Selenium may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Clinical research suggests that taking selenium 10 mcg/kg/day can increase bleeding times by increasing prostacyclin production, which inhibits platelet activity. Other clinical research suggests that taking selenium 75 mcg daily, in combination with ascorbic acid 600 mg, alpha-tocopherol 300 mg, and beta-carotene 27 mg, reduces platelet aggregation.

Likelihood Possible Evidence D
Barbiturates

Theoretically, selenium might prolong the sedating effects of barbiturates.
Laboratory research suggests that selenium can inhibit the hepatic metabolism of barbiturates. Selenium seems to prolong the sedative effect of pentobarbital in animal models.

Likelihood Possible Evidence D
Immunosuppressants

Theoretically, selenium supplementation may reduce the effectiveness of immunosuppressant therapy.
In vitro research and preliminary clinical evidence suggests that selenium may stimulate the immune system.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, selenium might interfere with warfarin activity.
Animal research suggests that selenium can increase warfarin activity. Selenium might interact with warfarin by displacing it from albumin binding sites, reducing its metabolism in the liver, or by decreasing production of vitamin K-dependent clotting factors. Selenium can also prolong bleeding times in humans by increasing prostacyclin production, which inhibits platelet activity.

Likelihood Possible Evidence D
Contraceptive Drugs

Contraceptive drugs might increase levels of selenium, although the clinical significance of this effect is unclear.
Some research suggests that oral contraceptives increase serum selenium levels in women taking oral contraceptives; however, other research shows no change in selenium levels. It is suggested that an increase could be due to increased carrier proteins, indicating a redistribution of selenium rather than a change in total body selenium.

Likelihood Possible Evidence B
Niacin

Selenium might reduce the beneficial effects of niacin on high-density lipoprotein (HDL) levels.
A combination of niacin and simvastatin (Zocor) effectively raises HDL cholesterol levels in patients with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50% in patients with coronary disease. It is not known whether this adverse effect is due to a single antioxidant such as selenium, or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A
Selenium full monograph & interactions

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

Folic Acid7 drug types · 40 drugs

5-Fluorouracil

Theoretically, high doses of folic acid might increase the toxicity of 5-fluorouracil.
Increases in gastrointestinal side effects of 5-fluorouracil, such as stomatitis and diarrhea, have been described in two clinical studies when leucovorin, a form of folic acid, was administered with 5-fluorouracil.

Likelihood Possible Evidence D
Capecitabine (Xeloda)

Use of high-dose folic acid might contribute to capecitabine toxicity.
Clinical research suggests that higher serum folate levels are associated with an increased risk for moderate or severe toxicity during capecitabine-based treatment for colorectal cancer. Additionally, in one case report, taking folic acid 15 mg daily might have contributed to increased toxicity, including severe diarrhea, vomiting, edema, hand-foot syndrome, and eventually death, in a patient prescribed capecitabine.

Likelihood Possible Evidence D
Methotrexate (Trexall, Others)

Folic acid might reduce the efficacy of methotrexate as a cancer treatment when given concurrently.
Methotrexate exerts its cytotoxic effects by preventing conversion of folic acid to the active form needed by cells. There is some evidence that folic acid supplements reduce the efficacy of methotrexate in the treatment of acute lymphoblastic leukemia, and theoretically they could reduce its efficacy in the treatment of other cancers. Advise cancer patients to consult their oncologist before using folic acid supplements. In patients treated with long-term, low-dose methotrexate for rheumatoid arthritis (RA) or psoriasis, folic acid supplements can reduce the incidence of side effects, without reducing efficacy.

Likelihood Probable Evidence B
Phenobarbital (Luminal)

Folic acid might have antagonistic effects on phenobarbital and increase the risk for seizures.
Folic acid can have direct convulsant activity in some people, reversing the effects of phenobarbital and worsening seizure control. Monitor closely for increased seizure activity.

Likelihood Probable Evidence B
Phenytoin (Dilantin)

Folic acid might reduce serum levels of phenytoin in some patients.
Folic acid may be a cofactor in phenytoin metabolism. Folic acid, in doses of 1 mg daily or more, can reduce serum levels of phenytoin in some patients. Increases in seizure frequency have been reported. If folic acid supplements are added to established phenytoin therapy, monitor serum phenytoin levels closely. If phenytoin and folic acid are started at the same time and continued together, adverse changes in phenytoin pharmacokinetics are avoided. Note that phenytoin also reduces serum folate levels.

Likelihood Probable Evidence B
Primidone (Mysoline)

Folic acid might have antagonistic effects on primidone and increase the risk for seizures.
Folic acid can have direct convulsant activity in some people, reversing the effects of primidone and worsening seizure control. Monitor closely for increased seizure activity. Note that primidone also reduces serum folate levels.

Likelihood Probable Evidence B
Pyrimethamine (Daraprim)

Folic acid might antagonize the effects of pyrimethamine.
Folic acid can antagonize the antiparasitic effects of pyrimethamine against toxoplasmosis and Pneumocystis carinii pneumonia. Folic acid doesn't antagonize the effects of pyrimethamine in the treatment of malaria, because malarial parasites cannot use exogenous folic acid. Use folinic acid as an alternative to folic acid when indicated.

Likelihood Probable Evidence D
Folic Acid 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 Grey + Defence Xtreme 2.0, from the product label.

COORGA Nutraceuticals

See all COORGA Nutraceuticals products
Name
COORGA Nutraceuticals Corporation
Street Address
1621 Central Ave.
City
Cheyenne
State
WY
ZipCode
82001
Phone Number
800-288-7729
Web Address
www.greydefence.com
Pharmacist Counseling Corner

Grey + Defence Xtreme 2.0 by COORGA Nutraceuticals: Common Questions

Does Grey + Defence Xtreme 2.0 by COORGA Nutraceuticals interact with any medications?
Yes. Based on its ingredients, Grey + Defence Xtreme 2.0 has a known interaction with 525 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Grey + Defence Xtreme 2.0 contains 5 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.
Can I take this if I'm pregnant?
Vitamin B6 is sometimes used for morning sickness but only under a doctor's guidance. Folic acid is recommended at standard prenatal doses to prevent birth defects. Vitamin B12 is needed in pregnancy. We don't have safety data on file for selenium or GD Gris Verso in pregnancy. Talk with your OB or pharmacist to make sure the dose is right for you.
What are the main side effects I should watch for?
At normal doses, the most common side effects are headache, nausea, heartburn, and stomach upset. With high-dose vitamin B6 (especially over 1,000 mg daily), nerve damage (numbness and tingling) is a serious risk. Excess selenium can cause rash, fatigue, and hair or nail problems. Stop and contact your doctor if you develop numbness, tingling, or severe rash.
Is it safe to take a lot of this for better results?
No. B6 is safe under 100 mg daily but high doses cause nerve damage. Selenium's safe upper limit is 400 mcg daily; excess is toxic. Folic acid at very high doses can cause confusion and sleep problems. More is not better — stick to the label dose and ask your pharmacist if you're considering higher amounts.
What's GD Gris Verso in this formula?
GD Gris Verso is one of the active ingredients, but we don't have data on file about what it does, how it works, or how it might interact with medications. Ask the manufacturer or your pharmacist for more information about this ingredient.
Will this interact with my blood thinner or diabetes medication?
Selenium in this product may increase bleeding risk with blood thinners like warfarin or other anticoagulants. Vitamin B12 can lower your B12 levels if you take metformin long-term. Use the medication checker on this page to search your exact drugs, and tell your pharmacist before you start.
Can I use this if I take seizure medication?
This product carries Moderate interactions with seizure drugs like phenobarbital and phenytoin — high B6 and folic acid can reduce the drug's blood levels and weaken seizure control. Do not start this without checking with your doctor or pharmacist first.

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.

Grey + Defence Xtreme 2.0 label
Go deeper

The Full Monographs Behind Grey + Defence Xtreme 2.0’s Ingredients

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

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

Folic Acid

Interacts with 40 drugs

Folic acid is the man-made form of vitamin B9 and is one of the most well-studied supplements, especially for preventing serious birth defects when taken before and during early pregnancy. I...

Read the full Folic Acid monograph → 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

Selenium

Interacts with 321 drugs

Selenium is an essential trace mineral your body needs in small amounts for thyroid function, antioxidant defense, and immune health. Most people who eat a varied diet get enough, and supple...

Read the full Selenium monograph →
Sources

Sources & How We Checked

Grey + Defence Xtreme 2.0'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 154 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 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
  19. Vasdev, S., Ford, C. A., Parai, S., Longerich, L., and Gadag, V. Dietary vitamin B6 supplementation attenuates hypertension in spontaneously hypertensive rats. Mol.Cell Biochem. 1999;200(1-2):155-162.
  20. de, Vogel S., Dindore, V., van, Engeland M., Goldbohm, R. A., van den Brandt, P. A., and Weijenberg, M. P. Dietary folate, methionine, riboflavin, and vitamin B-6 and risk of sporadic colorectal cancer. J Nutr 2008;138(12):2372-2378. PubMed
  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
  22. Aybak, M., Sermet, A., Ayyildiz, M. O., and Karakilcik, A. Z. Effect of oral pyridoxine hydrochloride supplementation on arterial blood pressure in patients with essential hypertension. Arzneimittelforschung. 1995;45(12):1271-1273.
  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
  26. Hankey GJ, Eikelboom JW, Yi Q, et al. Treatment with B vitamins and incidence of cancer in patients with previous stroke or transient ischemic attack: Results of a randomized placebo-controlled trial. Stroke 2012;43(6):1572-7. PubMed
  27. Hoyer-Kuhn H, Kohbrok S, Volland R, Franklin J, Hero B, Beck BB, Hoppe B. Vitamin B6 in primary hyperoxaluria I: first prospective trial after 40 years of practice. Clin J Am Soc Nephrol. 2014 Mar;9(3):468-77. PubMed
  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
  29. Gupta M, Gallante B, Bamberger JN, et al. Prospective randomized evaluation of idiopathic hyperoxaluria treatments. J Endourol 2021;35(12):1844-1851. PubMed
  30. Li H, Chen M, Liang S, et al. Excessive vitamin B6 during treatment is related to poor prognosis of patients with nasopharyngeal carcinoma: A U-shaped distribution suggests low dose supplement. Clin Nutr 2021;40(4):2293-2300. PubMed
  31. Tanigawa J, Nabatame S, Tominaga K, et al. High-dose pyridoxine treatment for inherited glycosylphosphatidylinositol deficiency. Brain Dev 2021;43(6):680-687. PubMed
  32. Committee on Practice Bulletins-Obstetrics. ACOG Practice Bulletin No. 189: Nausea And Vomiting Of Pregnancy. Obstet Gynecol. 2018;131(1):e15-e30. PubMed

See these in context on the Vitamin B6 monograph →

Folic Acid 56 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Duhra P. Treatment of gastrointestinal symptoms associated with methotrexate therapy for psoriasis. J Am Acad Dermatol 1993;28:466-9. PubMed
  3. Morgan SL, Baggott JE, Vaughn WH, et al. Supplementation with folic acid during methotrexate therapy for rheumatoid arthritis. A double-blind, placebo-controlled trial. Ann Intern Med 1994;121:833-41. PubMed
  4. Froscher W, Maier V, Laage M, et al. Folate deficiency, anticonvulsant drugs, and psychiatric morbidity. Clin Neuropharmacol 1995;18:165-82. PubMed
  5. Lewis DP, Van Dyke DC, Willhite LA, et al. Phenytoin-folic acid interaction. Ann Pharmacother 1995;29:726-35. PubMed
  6. Berg MJ, Stumbo PJ, Chenard CA, et al. Folic acid improves phenytoin pharmacokinetics. J Am Diet Assoc 1995;95:352-6. PubMed
  7. Berg MJ, Fincham RW, Ebert BE, et al. Phenytoin pharmacokinetics: Before and after folic acid administration. Epilepsia 1992;33:712-20. PubMed
  8. Shafer RB, Nuttall FQ. Calcium and folic acid absorption in patients taking anticonvulsant drugs. J Clin Endocrinol Metab 1975;41:1125-9. PubMed
  9. Leeb BF, Witzmann G, Ogris E, et al. Folic acid and cyanocobalamin levels in serum and erythrocytes during low-dose methotrexate therapy of rheumatoid arthritis and psoriatic arthritis patients. Clin Exp Rheumatol 1995;13:459-63.
  10. Morgan SL, Baggott JE, Lee JY, Alarcón GS. Folic acid supplementation prevents deficient blood folate levels and hyperhomocysteinemia during longterm, low dose methotrexate therapy for rheumatoid arthritis: implications for cardiovascular disease preventi
  11. Dijkmans BA. Folate supplementation and methotrexate. Br J Rheumatol 1995;34:1172-4. PubMed
  12. Segal S, Kaminski S. Drug-nutrient interactions. American Druggist 1996 Jul;42-8.
  13. Lambie DG, Johnson RH. Drugs and folate metabolism. Drugs 1985;30:145-55. PubMed
  14. Amer College of Rheumatology ad hoc committee on clinical guidelines. Guidelines for monitoring drug therapy in rheumatoid arthritis. Arthritis Rheum 1996;39:723-31. DOI
  15. Suitor CW, Bailey LB. Dietary folate equivalents: interpretation and application. J Am Diet Assoc 2000;100:88-94. PubMed
  16. 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
  17. Sandoval M, Charbonnet RM, Okuhama NN, et al. Cat's claw inhibits TNFalpha production and scavenges free radicals: role in cytoprotection. Free Radic Biol Med 2000;29:71-78.
  18. Antony AC. Megaloblastic Anemias. In: Hoffman R, Benz Jr EJ, Shattil SJ, et al. Hematology: Basic Principles and Practice. 3rd ed. New York, NY: Churchill Livingstone 2000: 451-79.
  19. Reynolds EH. Neurological aspects of folate and vitamin B12 metabolism. Clin Haematol 1976;5:661-96. DOI
  20. Reynolds EH. Folate metabolism and anticonvulsant therapy. Proc R Soc Med 1974;67:68.
  21. Ortiz Z, Shea B, Suarez Almazor M, et al. Folic acid and folinic acid for reducing side effects in patients receiving methotrexate for rheumatoid arthritis (Cochrane Review). Cochrane Database Syst Rev 2000;2:CD000951. PubMed
  22. Van Delden C, Hirschel B. Folinic acid supplements to pyrimethamine-sulfadiazine for Toxoplasma encephalitis are associated with better outcome (letter). J Infect Dis 1996;173:1294-5. PubMed
  23. Schroder H, Clausen N, Ostergard E, Pressler T. Folic acid supplements in vitamin tablets: a determinant of hematological drug tolerance in maintenance therapy of childhood acute lymphoblastic leukemia. Ped Hematol Oncol 1986;3:241-7. PubMed
  24. 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
  25. Morris MC, Evans DA, Bienias JL, et al. Dietary folate and vitamin B12 intake and cognitive decline among community-dwelling older persons. Arch Neurol 2005;62:641-5. PubMed
  26. Bonaa KH, Njolstad I, Ueland PM, et al. NORVIT: Homocysteine lowering and cardiovascular events after acute myocardial infarction. N Enlg J Med 2006;354:1578-88. PubMed
  27. Lawson KA, Wright ME, Subar A, et al. Multivitamin use and risk of prostate cancer in the National Institutes of Health-AARP Diet and Health Study. J Natl Cancer Inst 2007;99:754-64. PubMed
  28. Figueiredo JC, Grau MV, Haile RW, et al. Folic acid and risk of prostate cancer: Results from a randomized clinical trial. J Natl Cancer Inst 2009;101:432-5. PubMed
  29. Clippe C, Freyer G, Milano G, Trillet-Lenoir V. Lethal toxicity of capecitabine due to abusive folic acid prescription. Clin Oncol (R Coll Radiol) 2003;15:299-300. PubMed
  30. Bedford Laboratories. Leucovorin calcium [package insert]. Bedford, OH. September 2008. Available at: http://www.bedfordlabs.com/BedfordLabsWeb/products/inserts/LCV-P02.pdf.
  31. Ebbing M, Bonaa KH, Nygard O, et al. Cancer incidence and mortality after treatment with folic acid and vitamin B12. JAMA 2009;302:2119-26.
  32. Haberg, S. E., London, S. J., Stigum, H., Nafstad, P., and Nystad, W. Folic acid supplements in pregnancy and early childhood respiratory health. Arch Dis.Child 2009;94(3):180-184. PubMed
  33. Whitrow, M. J., Moore, V. M., Rumbold, A. R., and Davies, M. J. Effect of supplemental folic acid in pregnancy on childhood asthma: a prospective birth cohort study. Am J Epidemiol. 12-15-2009;170(12):1486-1493. PubMed
  34. 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
  35. Baggott, J. E., Oster, R. A., and Tamura, T. Meta-analysis of cancer risk in folic acid supplementation trials. Cancer Epidemiol. 2012;36(1):78-81. PubMed
  36. 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
  37. Hankey GJ, Eikelboom JW, Yi Q, et al. Treatment with B vitamins and incidence of cancer in patients with previous stroke or transient ischemic attack: Results of a randomized placebo-controlled trial. Stroke 2012;43(6):1572-7. PubMed
  38. Taneja S, Strand TA, Kumar T, et al. Folic acid and vitamin B-12 supplementation and common infections in 6-30-mo-old children in India: a randomized placebo-controlled trial. Am J Clin Nutr 2013;98(3):731-7. PubMed
  39. van Wijngaarden JP, Swart KM, Enneman AW, et al. Effect of daily vitamin B-12 and folic acid supplementation on fracture incidence in elderly individuals with an elevated plasma homocysteine concentration: B-PROOF, a randomized controlled trial. Am J Clin
  40. Qin X, Fan F, Cui Y, Chen F, Chen Y, Cheng X, Li Y, Wang B, Xu X, Xu X, Huo Y, Wang X. Folic acid supplementation with and without vitamin B6 and revascularization risk: a meta-analysis of randomized controlled trials. Clin Nutr. 2014;33(4):603-12. PubMed
  41. Crider KS, Cordero AM, Qi YP, Mulinare J, Dowling NF, Berry RJ. Prenatal folic acid and risk of asthma in children: a systematic review and meta-analysis. Am J Clin Nutr. 2013;98(5):1272-81. PubMed
  42. Matsubara S, Imai K, Murayama K, Higashizawa T. Severe liver dysfunction during nausea and vomiting of pregnancy: folic acid supplement as a suggested culprit. J Obstet Gynaecol. 2012;32(7):701-2. PubMed
  43. Qin X, Cui Y, Shen L, Sun N, Zhang Y, Li J, Xu X, Wang B, Xu X, Huo Y, Wang X. Folic acid supplementation and cancer risk: a meta-analysis of randomized controlled trials. Int J Cancer. 2013 1;133(5):1033-41. PubMed
  44. Tio M, Andrici J, Cox MR, Eslick GD. Folate intake and the risk of prostate cancer: a systematic review and meta-analysis. Prostate Cancer Prostatic Dis. 2014;17(3):213-9. PubMed
  45. Tomaszewski JJ, Richman EL, Sadetsky N, O'Keefe DS, Carroll PR, Davies BJ, Chan JM. Impact of folate intake on prostate cancer recurrence following definitive therapy: data from CaPSURE. J Urol. 2014;191(4):971-6. PubMed
  46. Valera-Gran D, García de la Hera M, Navarrete-Muñoz EM, Fernandez-Somoano A, Tardón A, Julvez J, Forns J, Lertxundi N, Ibarluzea JM, Murcia M, Rebagliato M, Vioque J; Infancia y Medio Ambiente (INMA) Project. Folic acid supplements during pregnancy and ch
  47. Van Der Woude DA, De Vries J, Van Wijk EM, Verzijl JM, Pijnenborg JM. A randomized controlled trial examining the addition of folic acid to iron supplementation in the treatment of postpartum anemia. Int J Gynaecol Obstet. 2014;126(2):101-5. PubMed
  48. Vila-Nova C, Wehby GL, Queirós FC, Chakraborty H, Félix TM, Goco N, Moore J, Gewehr EV, Lins L, Affonso CM, Murray JC. Periconceptional use of folic acid and risk of miscarriage - findings of the Oral Cleft Prevention Program in Brazil. J Perinat Med. 201 PubMed
  49. Vollset SE, Clarke R, Lewington S, Ebbing M, Halsey J, Lonn E, Armitage J, Manson JE, Hankey GJ, Spence JD, Galan P, Bønaa KH, Jamison R, Gaziano JM, Guarino P, Baron JA, Logan RF, Giovannucci EL, den Heijer M, Ueland PM, Bennett D, Collins R, Peto R; B-V
  50. Wehby GL, Félix TM, Goco N, Richieri-Costa A, Chakraborty H, Souza J, Pereira R, Padovani C, Moretti-Ferreira D, Murray JC. High dosage folic acid supplementation, oral cleft recurrence and fetal growth. Int J Environ Res Public Health. 2013 4;10(2):590-6 PubMed
  51. 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
  52. Liu J, Li Z, Ye R, Liu J, Ren A. Periconceptional folic acid supplementation and risk of parent-reported asthma in children at 4-6 years of age. ERJ Open Res. 2020;6(1):00250-2019. PubMed
  53. Houghton LA, Sherwood KL, Pawlosky R, Ito S, O'Connor DL. [6S]-5-Methyltetrahydrofolate is at least as effective as folic acid in preventing a decline in blood folate concentrations during lactation. Am J Clin Nutr. 2006 Apr;83(4):842-50. PubMed
  54. Houghton LA, Yang J, O'Connor DL. Unmetabolized folic acid and total folate concentrations in breast milk are unaffected by low-dose folate supplements. Am J Clin Nutr. 2009 Jan;89(1):216-20. PubMed
  55. Chan SL, Chan AWH, Mo F, et al. Association Between Serum Folate Level and Toxicity of Capecitabine During Treatment for Colorectal Cancer. Oncologist. 2018 Dec;23(12):1436-1445. PubMed
  56. Sarris J, Ravindran A, Yatham LN, et al. Clinician guidelines for the treatment of psychiatric disorders with nutraceuticals and phytoceuticals: The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety T

See these in context on the Folic Acid monograph →

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 →

Selenium 36 references
  1. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids. Washington, DC: National Academy Press, 2000. Available at: http://www.nap.edu/books/0309069351/html/.
  2. Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
  3. Trafikowska U, Zachara BA, Wiacek M, et al. Selenium supply and glutathione peroxidase activity in breastfed Polish infants. Acta Paediatr 1996;85:1143-5. PubMed
  4. Duffield-Lillico AJ, Slate EH, Reid ME, et al. Selenium supplementation and secondary prevention of nonmelanoma skin cancer in a randomized trial. J Natl Cancer Inst 2003;95:1477-81.. PubMed
  5. Cheung MC, Zhao XQ, Chait A, et al. Antioxidant supplements block the response of HDL to simvastatin-niacin therapy in patients with coronary artery disease and low HDL. Arterioscler Thromb Vasc Biol 2001;21:1320-6. PubMed
  6. Schiavon R, Freeman GE, Guidi GC, et al. Selenium enhances prostacyclin production by cultured endothelial cells: possible explanation for increased bleeding times in volunteers taking selenium as a dietary supplement. Thromb Res 1984;34:389-96. PubMed
  7. Davila JC, Edds GT, Osuna O, Simpson CF. Modification of the effects of aflatoxin B1 and warfarin in young pigs given selenium. Am J Vet Res 1983;44:1877-83. DOI
  8. Heese HD, Lawrence MA, Dempster WS, Pocock F. Reference concentrations of serum selenium and manganese in healthy nulliparas. S Afr Med J 1988;73:163-5.
  9. Lloyd B, Lloyd RS, Clayton BE. Effect of smoking, alcohol and other factors on the selenium status of a healthy population. J Epidemiol Commun Health 1983;37:213-7. PubMed
  10. Capel ID, Jenner M, Williams DC, et al. The effect of prolonged oral contraceptive steroid use on erythrocyte glutathione peroxidase activity. J Steroid Biochem 1981;14:729-32. PubMed
  11. Contempre B, Dumont JE, Ngo B, et al. Effect of selenium supplementation in hypothyroid subjects of an iodine and selenium deficient area: the possible danger of indiscriminate supplementation of iodine-deficient subjects with selenium. J Clin Endocrinol PubMed
  12. Hofbauer LC, Spitzweg C, Magerstadt RA, Heufelder AE. Selenium-induced thyroid dysfunction. Postgrad Med J 1997;73:103-4. PubMed
  13. Debski B, Milner JA. Dietary selenium supplementation prolongs pentobarbital induced hypnosis. J Nutr Biochem 2004;15:548-53. PubMed
  14. Ishikawa M, Sasaki M, Koiwai K, et al. Inhibition of hepatic mixed-function oxidase enzymes in mice by acute and chronic treatment with selenium. J Pharmacobiodyn 1992;15:377-85. PubMed
  15. Lippmann SM, Klein EA, Goodman PJ, et al. Effect of selenium and vitamin E on risk of prostate cancer and other cancers: the selenium and vitamin E cancer prevention trial (SELECT). JAMA 2009;301:39-51. DOI
  16. Reid SM, Middleton P, Cossich MC, Crowther CA. Interventions for clinical and subclinical hypothyroidism in pregnancy. Cochrane Database Syst Rev 2010;(7):CD007752. PubMed
  17. Vinceti, M., Wei, E. T., Malagoli, C., Bergomi, M., and Vivoli, G. Adverse health effects of selenium in humans. Rev.Environ.Health 2001;16(4):233-251. PubMed
  18. Abrams, C. K., Siram, S. M., Galsim, C., Johnson-Hamilton, H., Munford, F. L., and Mezghebe, H. Selenium deficiency in long-term total parenteral nutrition. Nutr Clin Pract 1992;7(4):175-178. PubMed
  19. Spiller, H. A. and Pfiefer, E. Two fatal cases of selenium toxicity. Forensic Sci Int 8-24-2007;171(1):67-72. PubMed
  20. Negro, R., Greco, G., Mangieri, T., Pezzarossa, A., Dazzi, D., and Hassan, H. The influence of selenium supplementation on postpartum thyroid status in pregnant women with thyroid peroxidase autoantibodies. J Clin Endocrinol.Metab 2007;92(4):1263-1268. PubMed
  21. Alexander, J. Selenium. Novartis.Found.Symp 2007;282:143-149.
  22. Salonen, J. T., Salonen, R., Seppanen, K., Rinta-Kiikka, S., Kuukka, M., Korpela, H., Alfthan, G., Kantola, M., and Schalch, W. Effects of antioxidant supplementation on platelet function: a randomized pair-matched, placebo-controlled, double-blind trial
  23. Kupka, R., Mugusi, F., Aboud, S., Msamanga, G. I., Finkelstein, J. L., Spiegelman, D., and Fawzi, W. W. Randomized, double-blind, placebo-controlled trial of selenium supplements among HIV-infected pregnant women in Tanzania: effects on maternal and chil
  24. Kamble, P., Mohsin, N., Jha, A., Date, A., Upadhaya, A., Mohammad, E., Khalil, M., Pakkyara, A., and Budruddin, M. Selenium intoxication with selenite broth resulting in acute renal failure and severe gastritis. Saudi.J Kidney Dis.Transpl. 2009;20(1):106
  25. Peretz, A., Neve, J., Desmedt, J., Duchateau, J., Dramaix, M., and Famaey, J. P. Lymphocyte response is enhanced by supplementation of elderly subjects with selenium-enriched yeast. Am.J Clin.Nutr. 1991;53(5):1323-1328. PubMed
  26. Kumpulainen, J., Salmenpera, L., Siimes, M. A., Koivistoinen, P., and Perheentupa, J. Selenium status of exclusively breast-fed infants as influenced by maternal organic or inorganic selenium supplementation. Am.J Clin.Nutr. 1985;42(5):829-835. PubMed
  27. Han, L. and Zhou, S. M. Selenium supplement in the prevention of pregnancy induced hypertension. Chin Med J (Engl) 1994;107(11):870-871.
  28. Kiremidjian-Schumacher, L., Roy, M., Wishe, H. I., Cohen, M. W., and Stotzky, G. Supplementation with selenium and human immune cell functions. II. Effect on cytotoxic lymphocytes and natural killer cells. Biol.Trace Elem.Res. 1994;41(1-2):115-127. PubMed
  29. Srivastava, A. K., Gupta, B. N., Bihari, V., and Gaur, J. S. Generalized hair loss and selenium exposure. Vet.Hum.Toxicol. 1995;37(5):468-469.
  30. Sudfeld CR, Aboud S, Kupka R, et al. Effect of selenium supplementation on HIV-1 RNA detection in breast milk of Tanzanian women. Nutrition 2014;30(9):1081-4. PubMed
  31. Rees K, Hartley L, Day C, et al. Selenium supplementation for the primary prevention of cardiovascular disease. Cochrane Database Syst Rev 2013;1:CD009671. PubMed
  32. Thompson PA, Ashbeck EL, Roe DJ, et al. Selenium Supplementation for Prevention of Colorectal Adenomas and Risk of Associated Type 2 Diabetes. J Natl Cancer Inst. 2016;108(12). PubMed
  33. Wichman J, Winther KH, Bonnema SJ, Hegedüs L. Selenium supplementation significantly reduces thyroid autoantibody levels in patients with chronic autoimmune thyroiditis: a systematic review and meta-analysis. Thyroid 2016;26(12):1681-92. PubMed
  34. Vinceti M, Filippini T, Rothman KJ. Selenium exposure and the risk of type 2 diabetes: a systematic review and meta-analysis. Eur J Epidemiol. 2018 Sep;33(9):789-810. Epub 2018 Jul 5. Review. PubMed
  35. Fallah S, Sani FV, Firoozrai M. Effect of contraceptive pill on the selenium and zinc status of healthy subjects. Contraception. 2009;80(1):40-3. PubMed
  36. Malpas CB, Vivash L, Genc S, et al. A Phase IIa Randomized Control Trial of VEL015 (Sodium Selenate) in Mild-Moderate Alzheimer's Disease. J Alzheimers Dis. 2016;54(1):223-232. PubMed

See these in context on the Selenium 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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