Best Vitamin K Supplements 2026: Cost per Effective Dose
Top pick for Vitamin K: Bluebonnet Vitamin K1 100 mcg — 100mcg per 1 caplet, $0.10/day.
Registry check · Vitamin K
Does anyone independently verify Vitamin K supplements?
Not one of these 4 products is listed by NSF, USP or Informed Sport as a verified product. Yet 1 of them advertise “third-party testing” without naming the certifier that did it — wording no public registry can confirm or deny. A factory-level claim such as “cGMP” audits the plant, not the Vitamin K bottle you would actually receive.
4 checked against all 5,317 US NSF, USP and Informed Sport listings, 2026-08-25. Full method and limitations.
What 3 Vitamin K labels show
Priced per day, these vitamin K products run $0.10 to $0.52 — a 5.2× gap between the cheapest and dearest vitamin K here, across 3 brands.
Servings here are close enough to compare directly, so the gap is a real one: Bluebonnet at $0.10 buys the same thing as Thorne at $0.52.
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.
| Product | Brand | Dose / Serving | Cost / Day | Certification (as labelled) | Pick | 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 | $0.52 | 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: Bluebonnet Vitamin K1 100 mcg
100mcg per 1 caplet. $0.10/day. 100 servings per container at $10.36.
The shelf · Vitamin K
The Vitamin K shelf is unusually consistent
Across 4 products from 4brands, the cheapest day is NOW Foods Vitamin K-2 100 mcg, Menaquinone-4 (MK-4) at 9¢ and the dearest Thorne Vitamin K (K1 + MK-4 + MK-7) at 52¢ — a gap of 5.8×, where categories on this site routinely run 15× or worse. With Vitamin K priced this tightly, the 4-brand question of who will verify their contents decides more than the price column does.
Method: the 4 Vitamin K products above, compared on label facts — serving size, servings per container, form, price. Not a dosing recommendation.
The evidence · Vitamin K
What the published reviews of Vitamin K concluded
- Perioperative Management of Vitamin K Antagonists and Direct Oral Anticoagulants: A Systematic Review and Meta-analysis. · Chest, 2023
“The certainty in the evidence supporting the perioperative management of anticoagulants remains limited.”
- The combination effect of vitamin K and vitamin D on human bone quality: a meta-analysis of randomized controlled trials. · Food & function, 2020
“The combination of vitamin K and D can significantly increase the total BMD and significantly decrease undercarboxylated osteocalcin, and a more favorable effect is expected when vitamin K2 is used.”
- Direct Oral Anticoagulants vs Vitamin K Antagonists in Patients With Antiphospholipid Syndromes: Meta-Analysis of Randomized Trials. · Journal of the American College of Cardiology, 2023
“Patients with thrombotic antiphospholipid syndrome randomized to DOACs compared with VKAs appear to have increased risk for arterial thrombosis. No significant differences were observed between patients randomized to DOACs vs VKAs in the risk of subsequent VTE or major bleeding.”
- An updated meta-analysis of novel oral anticoagulants versus vitamin K antagonists for uninterrupted anticoagulation in atrial fibrillation catheter ablation. · Heart rhythm, 2018
“In patients undergoing AF ablation, uninterrupted periprocedural NOACs are associated with a low incidence of stroke or TIA and a significant reduction in major bleeding as compared with uninterrupted VKAs.”
Method: PubMed searched in humans for systematic reviews and meta-analyses with Vitamin K in the title; these 4 of the 10 that qualified are shown with the authors’ own conclusion quoted rather than summarised. What it cannot tell you: whether Vitamin K will work for you — each of these reports an average across trials published 2018–2023, and null findings are shown here as readily as positive ones.
How these 3 Vitamin K products were ranked
Not one of these 3 vitamin K products could be confirmed in the NSF, USP or Informed Sport registries, so verification separates none of them and the ranking falls to cost per day at the labelled serving. Commission does not enter it: the rate is the same whichever vitamin K you buy. Full methodology.