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Dietary supplement

Vitamin K2 100 mcg Ingredients & Drug Interactions

by Natural Factors

Vitamin K2 100 mcg label
See full label image
Capsule Category: Vitamin
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Vitamin K2 100 mcg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

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

The interaction bottom line Most serious interaction: Major

Vitamin K2 100 mcg is a dietary supplement by Natural Factors 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 100 mcg by Natural Factors

Ask about any prescription or over-the-counter medication and we check it for interactions with Vitamin K2 100 mcg by Natural Factors — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Vitamin K2 100 mcg by Natural Factors

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

From our pharmacy team — supplement deep dive

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

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

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

This product contains one active ingredient: vitamin K2 at 100 mcg per capsule. Vitamin K is a fat-soluble vitamin that plays a role in blood clotting and bone health.

The capsule also holds microcrystalline cellulose, magnesium stearate, and a vegetarian capsule shell as inactive ingredients.

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: Supports bone and vascular health.
  • We looked for evidence on: Osteoporosis, Cardiovascular disease (CVD), Hemorrhagic disease, Vitamin K-dependent clotting factors deficiency (VKCFD), Warfarin anticoagulation, Bone density — and 2 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 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—including hypoprothrombinemia (a shortage of clotting proteins), vitamin K-dependent clotting factor deficiency, and hemorrhagic disease. It's also effective for managing warfarin anticoagulation when used under medical supervision.

For bone health, the evidence suggests it may be effective for osteoporosis, though more research is underway.

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 K is generally well tolerated in healthy people at normal dietary amounts and typical supplement doses. The most common side effects are mild: nausea, stomach upset, diarrhea, and abdominal pain.

The safety data advises that normal dietary amounts are fine, but you should check with your doctor before taking a supplement, especially if you have any medical conditions or take other medications.

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.

Warfarin (Coumadin) is the main one to watch. If you take this blood thinner, do not start vitamin K2 without talking to your provider first—the vitamin can reduce warfarin's protective effects and put you at risk for clots.

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 is a straightforward supplement for people who need to support their clotting or bone health—but it's not one you can just add without a conversation first. If you take warfarin or any blood thinner, you absolutely need to talk to your pharmacist or doctor before starting this.

Even if you don't take warfarin, a quick check with us is wise.

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 100 mcg, straight from the product label.

Brand Natural Factors
Barcode (UPC) 068958012940
Net contents 60 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD May 22, 2020
DSLD ID 220581
Product type Vitamin
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Vitamin K2 100 mcg by Natural Factors, 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)
UPC/BARCODE
068958012940
IngredientAmount% DV
Vitamin K2100 mcg83%

Other ingredients: Microcrystalline Cellulose, Vegetarian Capsule, Magnesium Stearate

Tap any ingredient to jump to its full detail below.

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

Dietary Supplement

Seals/Symbols

isura Non-GMO - Mass Spec Documentation Lab tested

Purity & Potency Guaranteed

Suggested/Recommended/Usage/Directions

Suggested Usage: 1 capsule per day or as directed by a health professional.

Precautions

Cautions: As with any supplement, consult your health professional before use if you are pregnant, breastfeeding, or trying to conceive, or if you are taking medication, have a medical condition, or anticipate a surgery.

Keep out of the reach of children.

Sealed for your protection. Do not use if seal is broken.

Contains soy.

Formulation

Supports bone and vascular health. Manufactured by Natural Factors to ensure safety and potency in accordance with Good Manufacturing Practices (GMP) of the FDA and Health Canada.

Contains no artificial colors, preservatives, or sweeteners; no dairy, sugar, wheat, gluten, yeast, corn, egg, fish, shellfish, animal products, salt, tree nuts, or GMOs.

Suitable for vegetarians/vegans.

Formula

Contains the bioactive and highly bioavailable MK-7 form.

Storage

For freshness, store in a cool, dry place.

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.

General Statements

Product of Canada Recyclable container and label.

Brand IP Statement(s)

Isura is trademark of ISURA.

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

See for yourself

Vitamin K2 100 mcg by Natural Factors label

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

Vitamin K2 100 mcg label

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

View the full label (PDF)
What’s inside

The Ingredients in Vitamin K2 100 mcg by Natural Factors

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

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

Vitamin K2

Interacts with
2 drugs
100 mcg per serving Form: Menaquinone-7, Natto

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, Vegetarian Capsule, Magnesium Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Vitamin K2 100 mcg by Natural Factors Drug Interactions

Want to check YOUR meds against Vitamin K2 100 mcg?

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

 Go to the checker
2Drugs
2 Major

Ingredients driving the most interactions

Vitamin K2 2

Individual Drug Interactions

The ingredients in Vitamin K2 100 mcg interact with 2 drugs. Click any drug to see the details.

1 of the 1 ingredient in Vitamin K2 100 mcg 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 100 mcg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Vitamin 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 100 mcg, from the product label.

Natural Factors

See all Natural Factors products
Name
Natural Factors
Street Address
14224 167th Avenue SE
City
Monroe
State
WA
ZipCode
98272
Pharmacist Counseling Corner

Vitamin K2 100 mcg by Natural Factors: Common Questions

Does Vitamin K2 100 mcg by Natural Factors interact with any medications?
Yes. Based on its ingredients, Vitamin K2 100 mcg 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 100 mcg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
What does vitamin K2 do in the body?
Vitamin K2 is essential for blood clotting—your body uses it to make the proteins that help stop bleeding. It also plays a role in bone health, which is why researchers are looking at it for osteoporosis.
Can I take this if I'm pregnant or breastfeeding?
Yes, vitamin K2 is rated as likely safe during pregnancy and lactation. That said, any supplement decision during pregnancy or while breastfeeding should involve your doctor—they know your full medical picture.
What are the side effects?
Taken by mouth, vitamin K is generally well tolerated. The most common side effects are mild and digestive: nausea, stomach upset, diarrhea, and abdominal pain. Most people don't experience any.
Why do I need to ask my doctor before taking this supplement?
Normal dietary amounts of vitamin K are fine, but supplements are a different story—especially if you take any medications. Warfarin, in particular, doesn't play well with extra vitamin K. A quick conversation with your pharmacist or doctor makes sure it's right for you.
Is vitamin K2 the same as vitamin K1?
No—they're different forms of vitamin K, and the facts we have on file cover vitamin K in general. If you have questions about how K2 specifically compares to K1, we can walk you through that at the counter.

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

Not sure if Vitamin K2 100 mcg is safe with your meds?

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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 100 mcg label
Go deeper

The Full Monographs Behind Vitamin K2 100 mcg’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 100 mcg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

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

The 11 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 11 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. 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.
  10. 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
  11. 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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