Best Vitamin K2 (MK-7) Supplement UK for Bone Health

About the author...

Will founded Supermushrooms after digging into the research behind mushroom and nootropic supplements. Every pick is checked against clinical dosing, extract standardisation, and real buyer reviews, and each star rating starts from a product's real Amazon score before being adjusted for formulation quality. Read more about how ratings are calculated.

The best vitamin K2 supplement in the UK is currently Nutravita Vitamin K2 Vital MK7 200mcg, praised for using the clinically studied K2VITAL branded ingredient at a dose above what most bone-health trials test. See the comparison below for how five other well-reviewed alternatives stack up depending on your priorities.

Vitamin K2 is the less familiar sibling of vitamin K1, the form most associated with green leafy vegetables and blood clotting. Where K1 stays largely in the liver, K2 travels to other tissues and activates two proteins, osteocalcin and matrix Gla-protein, that between them help guide calcium into bone and teeth while discouraging it from settling in artery walls. That dual role, supporting bone mineralisation on one hand and vascular flexibility on the other, is why K2 has become a popular pairing with vitamin D3, which increases how much calcium the gut absorbs in the first place but has no say over where that calcium ends up.

Most UK diets fall well short of the amounts of K2 used in research, since natto (fermented soybeans, a Japanese staple) is by far the richest natural source and rarely eaten here. Hard cheeses, egg yolks and some fermented dairy contain smaller amounts. That gap is the main reason K2 supplements exist at all, and it's also where buying decisions get genuinely confusing: menaquinone comes in several chain lengths (MK-4 through MK-13), supplement labels don't always specify which one they contain, and the difference between a "natural" and "synthetic" MK-7 source matters less than whether the molecule is in its active all-trans configuration.

Key Takeaways (TL;DR)

• Choose MK-7 over MK-4 for a supplement: its far longer half-life gives more stable blood levels from one daily dose.
• Confirm the product states all-trans MK-7, not just "natural" or "natto-derived" — the cis form is poorly used by the body.
• A branded ingredient like K2VITAL is one of the clearest quality signals available for K2 supplements.
• Match dose to the research range: most bone-health trials use 90-200mcg of MK-7 daily.
• NICE does not currently recommend vitamin K2 for treating or preventing osteoporosis — treat it as a complementary nutrient, not medical treatment.
• K2 works best paired with vitamin D3, which raises calcium absorption while K2 helps direct it into bone.
• Benefits show up in blood biomarkers within weeks, but meaningful bone-density changes take 6-12 months or longer.

How We Choose

We scored each product on whether its MK-7 dose sits within the range used in clinical research, whether the extract is confirmed all-trans and, where relevant, backed by a branded ingredient like K2VITAL, the manufacturer's quality standards (UK production, GMP, clean labelling), and value relative to the other five products here. Because K2's evidence base is still developing, we also weighted honesty of labelling and dose transparency heavily rather than rewarding the highest number on the front of the pack.

Quick Comparison

Each product's overall rating starts from its real Amazon UK customer rating, then gets adjusted (up to ±0.5) for dose versus clinical research, extract standardisation, manufacturing quality, and value. Click a product name to jump straight to its full review below.

Nutravita Vitamin K2 Vital MK7 200mcg

Best Overall — Clinically Studied K2VITAL Ingredient

based on 291 Amazon UK reviews (4.5★), adjusted for formulation quality

What We Love About the K2VITAL Ingredient

Most K2 listings simply say "MK-7" and leave it there. Nutravita instead names its source: K2VITAL, a branded, all-trans menaquinone-7 developed by Kappa Bioscience and used in the clinical trials that most K2 research actually relies on. That traceability matters in a category where cis/trans configuration is invisible on a label but makes a real difference to how much of the dose the body can use.

At 200mcg per tablet, the dose comfortably covers the 90-200mcg range used in most bone-health studies, and it does so in a single micro tablet rather than a capsule stuffed with filler. Review volume is modest next to some of the mass-market brands below, but the 4.5-star average holds up consistently across nearly 300 ratings.

All The Details on the K2VITAL Pick

Each vegan micro tablet delivers 200mcg of vitamin K2 as K2VITAL (all-trans MK-7). The pouch holds 180 tablets, roughly six months at one a day. Manufactured and certified in the UK, free from synthetic fillers or binders, and suitable for vegans.

WeightWorld Vitamin K2 MK7 200mcg

Best Value for a Full Year's Supply

based on 3453 Amazon UK reviews (4.7★), adjusted for formulation quality

What We Love About the Full-Year Value Pick

With 365 tablets in a single bottle, one order covers an entire year of daily K2 at the same 200mcg dose as the branded pick above. Nearly 3,500 ratings sit at 4.7 stars, making this by some distance the most reviewed product in this lineup and a genuinely reassuring track record for a value-focused brand.

Tablets are made in Britain, free from magnesium stearate, and non-GMO. If minimising cost-per-day and repeat ordering is the priority over a named branded ingredient, this is the more efficient route to the same 200mcg dose.

The Full-Year Pick: All The Details

Each tablet provides 200mcg of vitamin K2 as MK-7. 365 tablets per bottle, a full year's supply at one a day. Made in Britain, vegan, non-GMO, magnesium stearate-free.

Health4All Natural Vitamin K2 MK7 200mcg

Best Budget Natto-Derived MK-7

based on 945 Amazon UK reviews (4.6★), adjusted for formulation quality

What We Love About This Natto-Fermented Pick

Health4All fermented its MK-7 from natto beans rather than producing it synthetically, and states clearly on the label that the result is the all-trans form. Nearly 950 reviews at 4.6 stars give it a genuinely established history, the strongest review base of any product here besides WeightWorld's.

This is a small, Lancashire-based family brand rather than a household name, and the 180-tablet pouch keeps things simple: one tablet, 200mcg, no combination formula to think about.

Natto-Fermented Pick: All The Details

Each tablet delivers 200mcg of all-trans vitamin K2 (MK-7) from natto bean fermentation. 180 vegan tablets per pouch, around six months' supply. Manufactured in the UK to GMP standards.

BetterYou Vitamin K2 Daily Oral Spray

Best Pill-Free Format

based on 257 Amazon UK reviews (4.5★), adjusted for formulation quality

What We Love About the Spray Format

Three sprays deliver 180mcg of K2 straight onto the inner cheek, sidestepping the digestive tract entirely. Anyone who already struggles to swallow tablets, or takes a handful of other supplements already, will appreciate not adding one more capsule to the pile.

BetterYou has built its name on this delivery format across its whole vitamin D and K range, and the peppermint-flavoured spray has picked up 257 reviews at 4.5 stars. It's worth knowing upfront that this is the shortest-lasting option on this list: a bottle covers 60 daily doses, about two months, so repeat ordering comes round faster than with any of the tablet-based picks.

The Spray Format: All The Details

Each daily dose (3 sprays) provides 180mcg of vitamin K2 as MK-7. The 25ml bottle holds roughly 60 daily doses. Made in the UK, naturally flavoured with peppermint, suitable for vegetarians.

VitaBright Vitamin K2 MK7 100mcg

Best Entry-Level Dose

based on 144 Amazon UK reviews (4.6★), adjusted for formulation quality

What We Love About the Entry-Level Dose

At 100mcg per capsule, VitaBright sits at the lower end of what research actually uses, roughly half the dose of the 200mcg products above. That's not automatically a downside. Anyone starting K2 for the first time, or already getting some through cheese and egg yolks, might reasonably prefer to begin here rather than jump straight to 200mcg.

The capsules are natto-derived, made in Britain, and explicitly soya-free, which matters for the small number of people who react to soy-derived ingredients even in trace amounts. Review volume is the smallest in this list at 144, though the 4.6-star average is consistent with the larger brands here.

The Entry-Level Pick: All The Details

Each vegan capsule provides 100mcg of vitamin K2 (MK-7) from natto extract. 120 capsules per bottle, roughly four months' supply. Made in Britain, soya-free, no artificial fillers.

Igennus Triple Vitamin K Complex 2700mcg

Best Full-Spectrum K1 + K2 Complex

based on 276 Amazon UK reviews (4.5★), adjusted for formulation quality

The Case for a Three-Form Complex

Igennus takes a different approach to the rest of this list by combining three forms of vitamin K in one capsule: K1, MK-4, and MK-7, all stated as all-trans. K1 is the form most involved in liver-based clotting function, MK-4 has the shortest half-life but the most direct evidence in Japanese osteoporosis research, and MK-7 offers the longest-lasting blood levels of the three. Combining them is a genuinely different bet from betting everything on MK-7 alone, and it appeals to anyone who wants broader coverage rather than a single-form product.

The total daily dose across all three forms comes to 2700mcg, though buyers should note this figure spans three different compounds rather than representing 2700mcg of any single one. Igennus batch-tests its formulas and keeps the capsule free of magnesium stearate and silicon dioxide, and the product carries Vegan Society approval.

The Triple-K Complex: All The Details

Each vegan capsule provides a combined 2700mcg from three all-trans forms of vitamin K: K1, K2 as MK-4, and K2 as MK-7. 90 capsules per bottle, a three-month supply at one a day. GMP manufactured in the UK, Vegetarian Society and Vegan Society approved.

Best Vitamin K2 Supplement FAQ

What is vitamin K2 and how is it different from K1?

Vitamin K1 (phylloquinone) comes mainly from green leafy vegetables and is used predominantly by the liver for blood clotting. Vitamin K2 (menaquinone) is found in fermented foods and animal products, is absorbed differently, and circulates more widely around the body, where it activates proteins involved in directing calcium into bone and away from soft tissue and arterial walls. The two forms share a basic structure but function quite differently once absorbed.

What's the difference between MK-7 and MK-4?

Both are subtypes of vitamin K2, but they behave very differently once absorbed. MK-4 has a short half-life of only a couple of hours, so blood levels rise and fall quickly after a dose. MK-7 has a much longer side chain, giving it a half-life measured in days rather than hours, which keeps blood levels more stable across 24 hours from a single daily dose.¹ This is the main reason most modern K2 supplements, including five of the six reviewed above, use MK-7 rather than MK-4.

Does natto-derived MK-7 work better than synthetic MK-7?

Not necessarily. What actually matters is whether the MK-7 is in its all-trans configuration, the form the body can use, rather than the cis form, which is poorly utilised. Research comparing synthetic all-trans MK-7 with fermentation (natto)-derived all-trans MK-7 found the two to be bioequivalent in blood level response.² "Natural" or "natto-derived" on a label is a reasonable quality signal, but checking for an explicit "all-trans" claim is the more reliable one, whichever source the product uses.

Does vitamin K2 actually help bone health?

The evidence is genuinely mixed rather than settled either way. A 3-year randomised, placebo-controlled trial in postmenopausal women with osteopenia found MK-7 supplementation improved bone mineral density and microarchitecture markers compared with placebo.³ A broader systematic review and meta-analysis of K2 trials in postmenopausal osteoporosis found supportive but inconsistent results across the pooled studies, with the authors calling for more long-term trials before drawing firm conclusions.⁴ Other individual trials have found no measurable effect on bone loss over shorter follow-up periods. Treat K2 as a nutrient with a plausible, partially supported role in bone metabolism rather than a settled treatment.

Does NICE recommend vitamin K2 for osteoporosis?

No. UK clinical guidance does not currently recommend vitamin K or K2 supplementation as a standard treatment or preventive measure for osteoporosis, and it isn't part of NHS fracture-risk management pathways. This is worth being upfront about: K2 supplementation is a reasonable, low-risk nutritional choice for general bone and cardiovascular support, but it is not a substitute for calcium, vitamin D, bone-density scanning, or prescribed osteoporosis medication where these are clinically indicated. Anyone with diagnosed osteoporosis or osteopenia should follow their GP's or specialist's guidance rather than treating a K2 supplement as equivalent care.

How much vitamin K2 should I take, and is it safe with blood thinners?

Most of the research behind the products reviewed above uses doses between 90mcg and 200mcg of MK-7 daily; there's no official UK reference intake for K2 specifically. The one genuinely important safety point concerns warfarin and other vitamin K antagonist anticoagulants: these drugs work by blocking vitamin K's clotting function, so introducing a new, consistent source of vitamin K (K1 or K2) can interfere with dosing and INR stability.⁵ Anyone on warfarin or a similar anticoagulant should speak to their prescribing doctor before starting any vitamin K supplement, K2 included.

How long does vitamin K2 take to work?

Blood markers of vitamin K status, such as undercarboxylated osteocalcin, typically shift within a few weeks of consistent daily supplementation. Structural changes in bone density or cardiovascular calcification markers are a much slower story, with the clinical trials showing measurable differences generally running six months to three years. K2 isn't a supplement with a noticeable subjective effect; its benefit, where present, shows up in lab measurements and long-term outcomes rather than how you feel day to day.

Should I take vitamin K2 alongside vitamin D3?

This is one of the more sensible supplement pairings available, and it's a big part of why so many combination D3+K2 products exist. Vitamin D increases how much calcium the gut absorbs from food; vitamin K2 then helps direct that calcium into bone and teeth rather than leaving it to accumulate in arterial walls and soft tissue.⁶ If you're already taking a vitamin D supplement, our best vitamin D supplement guide covers several combined D3+K2 products, or you can pair a standalone D3 with any of the K2-only products reviewed above.

The Best Vitamin K2 Supplement for You

If you want the clearest quality signal available in this category, Nutravita's K2VITAL-branded tablet gives you a named, clinically studied ingredient at a research-relevant dose. WeightWorld and Health4All cover the same 200mcg MK-7 dose at a more accessible price, with WeightWorld's year-long supply particularly suited to anyone who doesn't want to reorder every few months. BetterYou's spray and VitaBright's lower-dose capsule both suit specific situations, tablet-avoidance and a gentler starting dose respectively, while Igennus's three-form complex is worth a look if you'd rather cover K1, MK-4, and MK-7 in one product than commit to MK-7 alone.

Whichever you choose, keep the evidence in perspective: K2 is a genuinely interesting nutrient with a plausible role in directing calcium toward bone rather than arteries, but it sits alongside good calcium intake, adequate vitamin D, weight-bearing exercise, and medical care, not in place of any of them.