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Dietary supplement

Natural Vitamin K2 45 mcg Ingredients & Drug Interactions

by Doctor's Best

Natural Vitamin K2 45 mcg label
See full label image
Capsule Category: Vitamin
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 30, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Natural Vitamin K2 45 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

Natural Vitamin K2 45 mcg is a dietary supplement by Doctor's Best 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 K. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Natural Vitamin K2 45 mcg by Doctor's Best

Ask about any prescription or over-the-counter medication and we check it for interactions with Natural Vitamin K2 45 mcg by Doctor's Best — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Natural Vitamin K2 45 mcg by Doctor's Best

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

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Aug 27, 2026

What’s inside

Partial disclosure
Ingredient Transparency · database check
Partial

Most active ingredients list an amount, but at least one is hidden in a blend or missing.

Why this rating?
  • The label discloses an exact amount for 1 of its 2 active ingredients.
  • “Vitamin K” is listed as a grouped ingredient — the label gives one combined amount (45 mcg) without saying how much of each component you get.

This product contains 2 active ingredients: vitamin K2 from MenaQ7 (a branded form of K2), supplying 45 mcg per capsule. Vitamin K is a fat-soluble vitamin your body needs to make clotting factors—proteins that help your blood clot when you're injured.

It also plays a role in bone health. The capsule also contains inactive ingredients: cellulose, vegetable capsule material, magnesium stearate, and silicon dioxide.

Does it work?

Moderate 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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: healthy bones and soft tissue.
  • We looked for evidence on: Osteoporosis, bone density, bone strength, bone health.
  • The strongest evidence on file: Vitamin K is rated "Possibly Effective" for Osteoporosis (Natural Medicines).

Vitamin K2 is rated effective for correcting vitamin K deficiency-related clotting problems, including low clotting factor levels and a bleeding disorder called hypoprothrombinemia. It's also rated effective for managing warfarin dosing and reversing excess warfarin effects.

For bone health, vitamin K2 is rated possibly effective for osteoporosis, meaning the evidence suggests it may help but isn't yet definitive.

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 typical supplement doses. The most common side effects are mild and gastrointestinal: nausea, stomach upset, abdominal pain, and diarrhea.

These occur in a small number of users and are rarely serious. Vitamin K2 is rated likely safe during pregnancy and lactation.

Normal dietary amounts are fine, but talk with your doctor before taking supplements while pregnant or nursing.

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.

Blood thinners—especially warfarin (Coumadin)—are the main concern. Vitamin K2 can reduce how well warfarin works to prevent clots.

Check with your doctor or pharmacist before combining this product with any blood thinner.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glancePartially disclosed formula with some supporting evidence for its stated purpose. Major medication interactions have been identified, and safety information is well characterized.

This supplement is worth considering if you have a vitamin K deficiency or if your doctor recommends it for bone health support. If you take warfarin or any blood thinner, do not start it without clearing it with your doctor first—vitamin K can reduce how well your medication works.

Talk with your doctor or pharmacist before adding this to your routine, especially if you take any blood thinners or have a bleeding disorder.

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

Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Sep 25, 2013.

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 Natural Vitamin K2 45 mcg, straight from the product label.

Brand Doctor's Best
Barcode (UPC) 753950002357
Net contents 10 Veggie Cap(s); 45 mcg
Market status On market
Date entered into DSLD Sep 25, 2013
DSLD ID 25514
Product type Vitamin
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Vegetarian, Adult (18 - 50 Years)
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 Natural Vitamin K2 45 mcg by Doctor's Best, 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
10
UPC/BARCODE
753950002357
IngredientAmount% DV
Vitamin K45 mcg56%
Vitamin K20 NP--
from 45 mcg of MenaQ7(TM)45 mcg--

Other ingredients: Cellulose, Vegetable Capsule, Magnesium Stearate, Silicon Dioxide

Tap any ingredient to jump to its full detail below.

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

Suitable for Vegetarians

General Statements

CONTAINS NOTHING OTHER THAN LISTED INGREDIENTS

SUPERIOR FORM OF VITAMIN K FOR HEALTHY BONES AND SOFT TISSUE*

General

R 08/10

Seals/Symbols

MenaQ7(R) Natural Vitamin K2

Suggested/Recommended/Usage/Directions

Suggested Adult Use: Take 1 capsule daily.

Formula

Caution: This product contains vitamin K.

Precautions

Consult your physician if using blood-thinning medications such as coumarin/warfarin.

Caution: This product contains vitamin K.

FDA Statement of Identity

Dietary Supplement

Brand IP Statement(s)

Science-Based Nutrition(TM)

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

See for yourself

Natural Vitamin K2 45 mcg by Doctor's Best label

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

Natural Vitamin K2 45 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 Natural Vitamin K2 45 mcg by Doctor's Best

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 container10 Amounts shown are per serving.

Vitamin K

Interacts with
2 drugs
45 mcg per serving

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 K monograph & interactions

Other (inactive) ingredients: Cellulose, Vegetable Capsule, Magnesium Stearate, Silicon Dioxide. These complete the product’s ingredient list but are not active constituents.

Interaction report

Natural Vitamin K2 45 mcg by Doctor's Best Drug Interactions

Want to check YOUR meds against Natural Vitamin K2 45 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 K 2

Individual Drug Interactions

The ingredients in Natural Vitamin K2 45 mcg interact with 2 drugs. Click any drug to see the details.

1 of the 1 ingredient in Natural Vitamin K2 45 mcg interact with drugs. Each result below shows which ingredient is responsible. Vitamin K

Each ingredient & the kinds of drugs it affects

For each ingredient in Natural Vitamin K2 45 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 K1 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 K full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Natural Vitamin K2 45 mcg, from the product label.

Doctor's Best

See all Doctor's Best products
Name
Doctor's Best, Inc.
City
San Clemente
State
CA
ZipCode
92673
Phone Number
(800) 777-2474
Web Address
www.drbvitamins.com
Pharmacist Counseling Corner

Natural Vitamin K2 45 mcg by Doctor's Best: Common Questions

Does Natural Vitamin K2 45 mcg by Doctor's Best interact with any medications?
Yes. Based on its ingredients, Natural Vitamin K2 45 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?
Natural Vitamin K2 45 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.
Will this interfere with my warfarin?
Yes—vitamin K2 can weaken warfarin's blood-thinning effect. If you take warfarin, talk to your doctor or pharmacist before starting this supplement. They may adjust your dose or recommend you skip it altogether.
What is vitamin K2, and why do I need it?
Vitamin K2 is a fat-soluble vitamin your body uses to make clotting factors—proteins needed for normal bleeding and clotting. It also supports bone health. Your body gets some from food; supplements provide extra if you're deficient or your doctor recommends them.
Can I take this if I'm pregnant or breastfeeding?
Vitamin K2 is rated likely safe during pregnancy and lactation. Normal dietary amounts are fine, but talk with your doctor before taking supplements—they can tell you whether it's right for your individual situation.
What side effects might I notice?
Most people tolerate it well. If side effects do occur, they're usually mild and gastrointestinal: nausea, stomach upset, abdominal pain, or diarrhea. These are uncommon and rarely serious.
Does this really help with bone health?
Vitamin K2 is rated possibly effective for osteoporosis, meaning research suggests it may help but the evidence isn't yet definitive. Your doctor can advise whether it makes sense for your bone health goals.

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

Not sure if Natural Vitamin K2 45 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.

Natural Vitamin K2 45 mcg label
Go deeper

The Full Monographs Behind Natural Vitamin K2 45 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

Natural Vitamin K2 45 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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