Best Vitamin K Supplements 2026: Cost per Effective Dose
Top pick for Vitamin K: NOW Foods Vitamin K-2 100 mcg, Menaquinone-4 (MK-4) — 100mcg per 1 veg capsule, $0.09/day.
All Vitamin K Supplements Compared
Vitamin K comes as K1 (phylloquinone, the form in leafy greens, mainly for clotting) and K2 (menaquinones, associated with bone and arterial research). Products labelled simply “vitamin K” may be either, or a blend, so check which menaquinone and how much before comparing prices. ⚠ Vitamin K in any form directly opposes warfarin, and changing your intake changes your anticoagulation — that conversation belongs with your prescriber, not a supplement label.
All 4 products sorted by cost per clinically-effective daily dose (lowest first). Dose, certification, and pricing verified against NIH DSLD and manufacturer data.
| Product | Brand | Dose / Serving | Cost / Day | Certification | Pick | Buy |
|---|---|---|---|---|---|---|
| NOW Foods Vitamin K-2 100 mcg, Menaquinone-4 (MK-4) | NOW Foods | 100mcg / 1 veg capsule | $0.09 | None | Buy | |
| Bluebonnet Vitamin K1 100 mcg | Bluebonnet | 100mcg / 1 caplet | $0.10 | None | Buy | |
| Nutricost Vitamin D3 (5,000 IU) + K2 (MK-7 100 mcg) | Nutricost | 100mcg / 1 softgel | $0.12 | None | Buy | |
| Thorne Vitamin K (K1 + MK-4 + MK-7) | Thorne | 100mcg / 1 capsule | $0.51 | Third-party tested | Buy |
In-Depth Vitamin K Guides
Go deeper on vitamin k — by goal, by form, and what the evidence actually supports:
Our Picks
Lowest Cost: NOW Foods Vitamin K-2 100 mcg, Menaquinone-4 (MK-4)
100mcg per 1 veg capsule. $0.09/day. 100 servings per container at $9.05.
How We Rank Vitamin K Supplements
Every product is evaluated on three criteria:
- Cost per day. Not cost per pill or cost per bottle — what it actually costs per day at the product's labelled serving. Where a category's servings differ in strength we flag it above the table, because cost per day is only comparable when the doses are.
- Third-party certification. USP Verified, NSF Certified for Sport, and ConsumerLab Approved indicate independent testing for purity, potency, and contaminants.
- Bioavailable form. We prioritize products using the specific chemical form shown to be most effective in published research.
Rankings are not influenced by affiliate commissions. We earn the same commission regardless of which product you choose. Read our full methodology.
Personalize Your Vitamin K Choice
Not sure which vitamin k supplement is right for you? Use our free tools:
- DNA Supplement Analyzer — upload 23andMe or AncestryDNA data to check for genetic variants affecting vitamin k metabolism. Runs entirely in your browser.
- Lab Results Interpreter — enter your blood test values to get personalized dosing recommendations.
- Supplement Stack Builder — build a complete protocol based on your age, sex, medications, and goals.
- Supplement Audit — already taking vitamin k? Check if you have the right form and dose.