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Dietary supplement

Vitamin K2 Ingredients & Drug Interactions

by Woodstock Vitamins

Vitamin K2 label
See full label image
Capsule Category: Vitamin
Most serious interaction: Major
Clinical methodology reviewed by · Updated Oct 7, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Vitamin K2 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: Major

Vitamin K2 is a dietary supplement by Woodstock Vitamins with 1 active ingredient. Its ingredients are commonly taken for supporting normal blood clotting, bone health, heart and vascular health.Based on those ingredients, 2 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Vitamin K2. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Vitamin K2 by Woodstock Vitamins

Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin K2 by Woodstock Vitamins — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Vitamin K2 by Woodstock Vitamins

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 Sep 24, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

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

This product contains 1 active ingredient: vitamin K2, a form of vitamin K that your body uses to make proteins needed for blood clotting and bone health. The capsule also holds inactive ingredients—microcrystalline cellulose, HPMC, stearic acid, magnesium stearate, and silica—which are binders and fillers that hold the capsule together.

Does it work?

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

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

Why this rating?
  • The label markets this product for: bone and heart health.
  • We looked for evidence on: Cardiovascular disease (CVD), Osteoporosis, Hemorrhagic disease, Hypoprothrombinemia, Vitamin K-dependent clotting factors deficiency (VKCFD), Warfarin anticoagulation — and 4 related terms.
  • The strongest evidence on file: Vitamin K is rated "Effective" for Hemorrhagic disease (Natural Medicines).
  • Also on file: Vitamin K is rated "Effective" for Hypoprothrombinemia, Warfarin anticoagulation, Vitamin K-dependent clotting factors deficiency (VKCFD).
  • Also on file: Vitamin K is rated "Possibly Effective" for Osteoporosis.

Vitamin K2 is effective for treating vitamin K deficiency conditions like hypoprothrombinemia, vitamin K-dependent clotting factor deficiency, hemorrhagic disease, and reversing excessive warfarin anticoagulation when that's medically necessary. For osteoporosis, the evidence is less settled—it's rated possibly effective, meaning there's some promise but not yet enough proof to call it a standard treatment.

The evidence, ingredient by ingredient Vitamin K

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

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

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

Taken by mouth, vitamin K2 is generally well tolerated in healthy people at dietary levels and most supplement doses. The most common side effects are mild: nausea, stomach upset, abdominal pain, and diarrhea—a small number of people experience these.

Serious side effects from oral vitamin K are very rare. Vitamin K2 is likely safe during pregnancy and while breastfeeding, so you don't need to avoid it on those grounds alone.

Side effects, ingredient by ingredient Vitamin K

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Vitamin K.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 2 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 with your doctor or pharmacist before taking this product if you use warfarin (Coumadin) or other blood thinners in its class. Vitamin K can reduce their effectiveness and compromise your blood clot prevention.

No other interactions are documented for the ingredients we could check.

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

Vitamin K2 works well for clotting and bone support, and it's generally easy on your stomach. The critical point: if you take warfarin or another blood thinner, do not start this supplement without your doctor's approval—vitamin K can interfere with how well these medications protect you.

Talk with your doctor or pharmacist before you begin, especially if you're on any blood-thinning medication.

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

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated May 22, 2020.

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

At a glance

General information

Key facts about Vitamin K2, straight from the product label.

Brand Woodstock Vitamins
Barcode (UPC) 669439857311
Net contents 60 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD May 22, 2020
DSLD ID 216988
Product type Vitamin
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Vitamin K2 by Woodstock Vitamins, 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
60
UPC/BARCODE
669439857311
IngredientAmount% DV
Vitamin K245 mcg38%

Other ingredients: Microcrystalline Cellulose, HPMC, Stearic Acid, Magnesium Stearate, Silica

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.
Suggested/Recommended/Usage/Directions

Directions: Take one capsule with a meal, one to two times daily, or as directed by your healthcare practitioner.

Precautions

Consult your healthcare practitioner prior to use.

Individuals taking medication should discuss potential interactions with their healthcare practitioner. Consider total vitamin intake (food + supplements) if you are taking blood-thinning medication.

Do not use if tamper seal is damaged.

Storage: Keep closed in a cool, dry place out of reach of children.

Formula

Vitamin K2 derived from non-GMO soybeans fermented with Bascillus subtilisnatto, is the most bioavailable and bioactive form of supplemental vitamin K2 available.

Natural vitamin K2 as MK-7

Formulation

Historical use and numerous studies have confirmed safety and efficacy for bone and heart health.

Does not contain: Wheat, gluten, yeast, soy protein, animal or dairy products, fish, shellfish, peanuts, tree nuts, egg, ingredients derived from genetically modified organisms (GMOs), artificial colors, artificial sweeteners, or artificial preservatives.

Manufactured in a GMP compliant facility.

FDA Disclaimer Statement

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

Storage

Storage: Keep closed in a cool, dry place out of reach of children.

FDA Statement of Identity

Dietary Supplement

General Statements

Professional use only.

This package is completely recyclable

Seals/Symbols

Vegetarian Caps

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

See for yourself

Vitamin K2 by Woodstock Vitamins label

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

Vitamin K2 label

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

View the full label (PDF)
What’s inside

The Ingredients in Vitamin K2 by Woodstock Vitamins

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

Vitamin K2

Interacts with
2 drugs
45 mcg per serving Form: Menaquinone-7

Vitamin K is an essential nutrient your body needs for normal blood clotting and to support healthy bones. Most people get enough from food, but suppl...

Vitamin K2 monograph & interactions

Other (inactive) ingredients: Microcrystalline Cellulose, HPMC, Stearic Acid, Magnesium Stearate, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Vitamin K2 by Woodstock Vitamins Drug Interactions

Want to check YOUR meds against Vitamin K2?

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
2Drugs
2 Major

Ingredients driving the most interactions

Vitamin K2 2

Individual Drug Interactions

The ingredients in Vitamin K2 interact with 2 drugs. Click any drug to see the details.

1 of the 1 ingredient in Vitamin K2 interact with drugs. Each result below shows which ingredient is responsible. Vitamin K2

Each ingredient & the kinds of drugs it affects

For each ingredient in Vitamin K2 with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Vitamin K21 drug type · 2 drugs

Warfarin (Coumadin)

Vitamin K can antagonize and reverse the therapeutic effects of warfarin.
Vitamin K antagonizes the effects of warfarin. Excessive vitamin K intake, either from supplements or from changes in the diet, can reduce the anticoagulant effect of warfarin.

Likelihood Likely Evidence C
Vitamin K2 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Vitamin K2, from the product label.

Woodstock Vitamins

See all Woodstock Vitamins products
Name
Village Vitality LLC
Street Address
79 Tinker Street Fl 2
City
Woodstock
State
NY
ZipCode
12498
Phone Number
(845) 521-7455
Web Address
www.WoodstockVitamins.com
Pharmacist Counseling Corner

Vitamin K2 by Woodstock Vitamins: Common Questions

Does Vitamin K2 by Woodstock Vitamins interact with any medications?
Yes. Based on its ingredients, Vitamin K2 has a known interaction with 2 medications, including 2 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Vitamin K2 contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Will vitamin K2 help my bones?
Vitamin K2 is rated possibly effective for osteoporosis, which means there's some evidence it may help, but it's not yet proven enough to be a standard treatment. Talk with your doctor about whether it fits into your bone health plan.
What side effects should I expect?
Most people tolerate vitamin K2 well. If you do get side effects, they're usually mild: nausea, stomach upset, belly pain, or diarrhea. Serious side effects are very rare when taken by mouth.
Is it safe to take while pregnant or breastfeeding?
Vitamin K2 is rated likely safe during pregnancy and while breastfeeding, so those aren't reasons to avoid it. Still, it's always smart to run any new supplement past your doctor or midwife during pregnancy.
What does vitamin K2 actually do in my body?
Your body uses vitamin K2 to make proteins that help blood clot and keep your bones strong. It's also involved in directing calcium to the right places in your body.
Can I take this if I'm on blood thinners?
Not without checking with your doctor first. Vitamin K can work against blood thinners like warfarin and reduce how well they protect you. Your doctor may adjust your dose or recommend against the supplement.

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

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

Vitamin K2 label
Go deeper

The Full Monographs Behind Vitamin K2’s Ingredients

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

Herb & supplement monograph

Vitamin K

Interacts with 2 drugs

Vitamin K is an essential nutrient your body needs for normal blood clotting and to support healthy bones. Most people get enough from food, but supplements are sometimes used for deficiency...

Read the full Vitamin K monograph →
Sources

Sources & How We Checked

Vitamin K2'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 12 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 K 12 references
  1. McEvoy GK, ed. AHFS Drug Information. Bethesda, MD: American Society of Health-System Pharmacists, 1998.
  2. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  3. Crowther MA, Ageno W, Garcia D, et al. Oral vitamin K versus placebo to correct excessive anticoagulation in patients receiving warfarin: a randomized trial. Ann Intern Med. 2009;150(5):293-300. PubMed
  4. Dietary vitamin K guidance: an effective strategy for stable control of oral anticoagulation? Nutr Rev. 2010;68(3):178-81. PubMed
  5. Kim JS, Nafziger AN, Gaedigk A, et al. Effects of oral vitamin K on S- and R-warfarin pharmacokinetics and pharmacodynamics: enhanced safety of warfarin as a CYP2C9 probe. J Clin Pharmacol. 2001 Jul;41(7):715-22. PubMed
  6. Riegert-Johnson, D. L. and Volcheck, G. W. The incidence of anaphylaxis following intravenous phytonadione (vitamin K1): a 5-year retrospective review. Ann.Allergy Asthma Immunol. 2002;89(4):400-406. PubMed
  7. Dezee, K. J., Shimeall, W. T., Douglas, K. M., Shumway, N. M., and O'malley, P. G. Treatment of excessive anticoagulation with phytonadione (vitamin K): a meta-analysis. Arch.Intern.Med. 2-27-2006;166(4):391-397. DOI
  8. Dentali, F., Ageno, W., and Crowther, M. Treatment of coumarin-associated coagulopathy: a systematic review and proposed treatment algorithms. J.Thromb.Haemost. 2006;4(9):1853-1863. PubMed
  9. Stevenson, M., Lloyd-Jones, M., and Papaioannou, D. Vitamin K to prevent fractures in older women: systematic review and economic evaluation. Health Technol.Assess. 2009;13(45):iii-134. PubMed
  10. Caluwé R, Vandecasteele S, Van Vlem B, Vermeer C, De Vriese AS. Vitamin K2 supplementation in haemodialysis patients: a randomized dose-finding study. Nephrol Dial Transplant. 2014;29(7):1385-90.
  11. Huang ZB, Wan SL, Lu YJ, Ning L, Liu C, Fan SW. Does vitamin K2 play a role in the prevention and treatment of osteoporosis for postmenopausal women: a meta-analysis of randomized controlled trials. Osteoporos Int. 2015;26(3):1175-86. PubMed
  12. Hunnali CR, Devi U, Kitchanan S, Sethuraman G. Three Different Regimens for Vitamin K Birth Prophylaxis in Infants Born Preterm: A Randomized Clinical Trial. J Pediatr 2023;255:98-104. PubMed

See these in context on the Vitamin K monograph →

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

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

© 2021 Therapeutic Research Center, LLC

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