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Best Vitamin K2 Supplements (2026)
Clinical dose: 90-200mcg MK-7 daily for bone and cardiovascular health; MK-4 requires higher doses (1,500mcg) due to shorter half-life - MK-7 is the preferred supplemental form
Bottom line
In our scoring, Vitamin K2 rates likely effective: the research is fairly solid for cardiovascular protection / arterial calcification reduction. Our top-scored product is NOW Foods Vitamin K-2 100mcg (85/100), about $0.17 a day at a clinical dose of 90-200mcg MK-7 daily for bone and cardiovascular health. Bottom line: a reasonable pick if it fits your goal. This is our opinion, not medical advice; talk to your clinician before starting.
Our Top Picks
NOW Foods Vitamin K-2 100mcg
$0.17/day at effective dose
Price checked 2026-08-09
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What to know first
Vitamin K2 is worth understanding before you buy, because two decisions do all the work and neither is the brand. The first is that K1 will not do K2's job. Eating more leafy greens gives you K1, which the body uses mainly for clotting. K2 activates the proteins that route calcium into bone and away from artery walls, and in the large Rotterdam cohort it was K2 intake, not K1, that tracked with markedly lower arterial calcification.
If you already take vitamin D3 this matters more, not less: D3 increases how much calcium you absorb, and K2 is what helps direct where it ends up. The second decision is the form, and it is the one this page really answers. MK-7 has a 72-hour half-life, so one capsule a day holds steady levels, and 90-200mcg is the studied range.
MK-4 clears in 1-2 hours and only shows results at pharmacological doses, the 45mg-a-day range used in Japanese bone trials. That is not a slightly stronger version of the same thing, it is a different protocol, and one product here sits in it. Everything else on this page is MK-7 between 90 and 150mcg, which is where almost every buyer should be.
One caution outranks all of the above: if you take warfarin or another vitamin K antagonist, do not start K2 without your doctor, and MK-7's long half-life makes it the trickiest form for that interaction. Our full vitamin K2 scorecard grades every product and every claim.
The Verdict
NOW Foods K-2 100mcg is our Top Pick at $0.17 a day. It is plain MK-7 at the studied dose from an NPA GMP-audited facility, it scores 85, and at a 120-count bottle it is also the cheapest thing here you can actually buy. For most people the decision genuinely ends there. Jarrow at $0.31 is the same idea at 90mcg and a reasonable alternative if it is what your shop stocks, though its price has climbed steadily through 2026. Sports Research at $0.40 is the pick if you want D3 in the same softgel, pairing 100mcg MK-7 with 5,000 IU of D3, which is a rational combination and saves a second bottle.
Pure Encapsulations PureHeart K2D at $0.80 does the same job at 150mcg MK-7 plus 1,000 IU D3 with hypoallergenic practitioner-grade testing, and you are paying roughly five times the Top Pick for that assurance. Then there is Thorne, and it needs stating plainly rather than ranking: at $0.94 a serving it is not an expensive version of these products, it is MK-4 liquid at 15mg a dose, which is the pharmacological range from the Japanese bone literature and about a hundred and fifty times the MK-7 dose everything else here delivers.
If a clinician has put you on that protocol, the metered dropper is genuinely the right tool. If you are buying K2 for the ordinary reason, it is the wrong shelf. Life Extension Super K is the cheapest per day on paper at $0.14 but is currently out of stock, and its added K1 is a complication rather than a bonus if K2 is what you came for.
MK-7 or MK-4, and why the difference is not a matter of degree
MK-7 has a half-life of about 72 hours, meaning the level in your blood takes three days to fall by half. One capsule a day therefore holds a steady level, which is why every trial that made K2 interesting for bone and arterial outcomes used it at 90 to 200mcg.
MK-4 clears in 1 to 2 hours. At the doses you would put in a normal capsule it never reaches a sustained level at all, which is why the Japanese literature that does show results uses roughly 45mg a day split across three doses. That is not a bigger capsule, it is a different regimen with different supervision.
So the page splits cleanly:
- NOW Foods, 100mcg MK-7, $0.17 a day. Our Top Pick and the cheapest buyable option.
- Jarrow, 90mcg MK-7, $0.31. Same idea, at the bottom of the studied range.
- Sports Research, 100mcg MK-7 plus 5,000 IU D3, $0.40. The combo pick.
- Pure Encapsulations, 150mcg MK-7 plus 1,000 IU D3, $0.80. Hypoallergenic and practitioner-grade.
- Life Extension, 100mcg in a broader K complex, $0.14, currently out of stock.
- Thorne, 15mg MK-4 liquid, $0.94 a serving. A different dose class, not a premium tier.
If you want the short version: buy MK-7 in the 90 to 200mcg range and ignore the rest of the label. The scorecard lists the exact form for every product.
Why K2 pairs with D3, and when the bundle is worth paying for
D3 raises calcium absorption. K2 activates the proteins that route that calcium into bone rather than leaving it available to deposit in artery walls. That is the mechanistic case for taking them together, and it is why a large share of the K2 market is sold as a D3 combination rather than as a standalone.
Two products here bundle it. Sports Research at $0.40 a day carries 5,000 IU of D3, which is a high daily dose and genuinely too much if you are already supplementing D3 separately. Pure Encapsulations at $0.80 carries 1,000 IU, a more moderate amount that is easier to layer on top of an existing routine.
The arithmetic is simple. If you do not currently take D3 and want to, a combination saves you a bottle and usually some money. If you already take D3 at a dose you have settled on, buy the plain MK-7 and keep control of the two separately. Our vitamin D3 picks cover that side if you are choosing both.
What the Evidence Says About Vitamin K2
How A-F grades work- BCardiovascular protection / arterial calcification reduction
- BBone mineral density improvement
- CFracture risk reduction
- CInsulin sensitivity / blood glucose
A = strong RCT evidence · B = moderate · C = limited · D = weak · F = no evidence.
Detailed Reviews
NOW Foods Vitamin K-2 100mcg
menaquinone-7 (MK-7) | 100mcg/serving | 120 servings
Price checked 2026-08-09
Reliable, affordable, properly dosed. Good starting point for K2 supplementation.
Jarrow Formulas MK-7 (Vitamin K2 as MK-7) 90mcg
menaquinone-7 (MK-7) | 90mcg/serving | 60 servings
Price checked 2026-08-09
Matches the dose used in the Knapen et al. bone density RCT. Once one of the best-priced MK-7s, though its price has risen well above the budget tier.
Pure Encapsulations PureHeart K2D
menaquinone-7 (MK-7) with cholecalciferol (D3) | 150mcg/serving | 60 servings
Price checked 2026-08-09
Best choice for those with food sensitivities, and the only product here that bundles D3 from a practitioner-grade brand. If you already take D3 separately, you are paying for something you have.
Also Scored
Thorne Vitamin K2 Liquid (MK-4)
$0.94/day | menaquinone-4 (MK-4), liquid with metered dropper
Price checked 2026-08-09
Full score breakdownSports Research Vitamin K2 + D3
$0.40/day | menaquinone-7 (MK-7)
Price checked 2026-08-07
Full score breakdownLife Extension Super K with Advanced K2 Complex
$0.14/day | MK-4 + MK-7 + K1 blend
Price checked 2026-06-08
Full score breakdownProduct prices and availability are accurate as of the date indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply.
What to Look For When Buying
- ✓K1 from leafy greens does not substitute for K2; they do different jobs
- ✓Buy MK-7, not MK-4: a 72-hour half-life means one capsule a day holds levels steady
- ✓90-200mcg of MK-7 is the studied range, and more is not better here
- ✓MK-4 only performs at pharmacological doses far above that range, so treat it as a separate protocol
- ✓If you already take D3, K2 is the natural pairing, and several products bundle the two
- ✓Do not start K2 alongside warfarin or another vitamin K antagonist without physician oversight
- ✓Give it 3 to 6 months before expecting bone-density measurements to move
Frequently Asked Questions
What is the difference between K1 and K2?
Vitamin K1 (phylloquinone) is found in leafy greens and primarily supports blood clotting. Vitamin K2 (menaquinone) is found in fermented foods and animal products and primarily activates proteins that regulate calcium distribution - directing it to bones and teeth while keeping it out of arteries. They are related but perform distinct functions. Getting enough K1 does not substitute for K2.
Should I take MK-4 or MK-7?
MK-7 is the preferred form for supplementation. Its half-life is 72 hours vs 1-2 hours for MK-4, so it maintains higher, more consistent tissue levels with a once-daily dose of 90-200mcg. MK-4 is used at pharmacological doses (45,000mcg) in Japanese osteoporosis treatment, but that dose is impractical and unnecessary for most supplementers. The bone and cardiovascular evidence for MK-7 at practical doses (90-180mcg) is solid.
Should I take K2 with Vitamin D3?
Yes - the combination is well-supported. Vitamin D3 increases calcium absorption from the gut. Without adequate K2, that extra absorbed calcium can end up in arteries rather than bones. K2 activates osteocalcin (bone-building) and Matrix Gla Protein (arterial protection), which require K2 for activation. Many practitioners and experts recommend taking K2 alongside any significant D3 supplementation. A ratio of 100mcg K2 per 2,000 IU D3 is commonly recommended.
What foods are highest in K2?
Natto (fermented soybeans) is by far the richest source of MK-7, with 850-1,000mcg per 100g serving. Other fermented cheeses contain MK-7 in smaller amounts. Egg yolks, liver, dark chicken meat, and full-fat dairy from grass-fed animals contain MK-4. Most modern Western diets provide very little K2 since natto is uncommon and much dairy and meat comes from grain-fed animals.
How long does it take for K2 to work for bone health?
Bone remodeling is slow. Studies measuring bone mineral density typically run 12-36 months. The 2015 Knapen et al. RCT ran for 3 years before showing significant BMD improvement with 180mcg MK-7. For cardiovascular markers like arterial stiffness, some studies show measurable changes at 6-12 months. This is a long-game supplement - consistent use over years is what produces measurable outcomes.
Sources
FDA Disclaimer: These statements have not been evaluated by the Food and Drug Administration. Dietary supplements are not intended to diagnose, treat, cure, or prevent any disease. Always consult with a qualified healthcare professional before starting any supplement regimen.