Vitamin K2 UK: MK-7 vs MK-4, Microgram Strengths and D3+K2 Combinations

Vitamin K2 is an unusual category. Search for it in the UK and most of what comes back is not vitamin K2 on its own — it is vitamin D3 with K2 added, sold as a single product. Of the K2 lines at NE Commerce, the large majority are combinations.

That makes the label harder to read than it looks, because you are now comparing two nutrients at once, in two different units, across products that use at least four different naming conventions for the same ingredient. Here is what each part of the label is actually telling you.

K1, K2 and why the label says menaquinone

Vitamin K comes in two families. Vitamin K1 is phylloquinone, the form found in green leafy vegetables, and it is what most general multivitamins use. Vitamin K2 is the menaquinone family, and this is the one sold as a standalone supplement.

Menaquinones are numbered by the length of their side chain, which is where MK‑4 and MK‑7 come from. If a label says "menaquinone‑7" it means MK‑7; if it says "menatetrenone" it means MK‑4. Some labels give you both the common name and the chemical one, which is helpful. Some give you neither and simply say "vitamin K2", which is not.

MK-7 and MK-4: the numbers give it away

You can usually tell which form you are looking at from the dose alone, because the two are labelled on completely different scales.

MK‑7 is dosed in micrograms. The strengths you will see on a UK shelf cluster around 45mcg, 100mcg and 180mcg. Doctor's Best Natural Vitamin K2 MK‑7 with MenaQ7 comes at 45mcg for £14.99 and 100mcg for £19.99, with a K2 plus D3 version at 180mcg for £31.99. Life Extension Low Dose Vitamin K2 (MK‑7) is 45mcg across 90 softgels at £16.99. Feel Supreme Vitamin K2 (MK7) is 60 capsules at £19.99.

MK‑4 is dosed in milligrams, and the jump is dramatic. Carlson Labs Vitamin K2 MK‑4 is 5mg — that is 5,000mcg, more than a hundred times a typical MK‑7 serving. It is priced at £26.72.

Because the scales differ so much, comparing an MK‑4 product to an MK‑7 product on the milligram figure alone is meaningless. They are formulated to different conventions, and their labels give different directions on how often to take them. Read the directions on each pack rather than assuming a bigger number is a better product.

MenaQ7, K2VITAL and other trade names

Names like MenaQ7 appear on a lot of K2 labels. These are ingredient trademarks — they identify which company supplied the raw material and to what specification, in the same way that Creapure does on a creatine tub or Kaneka does on ubiquinol.

A branded raw material tells you the manufacturer has bought a documented, specified ingredient rather than a generic one, and it usually indicates an all‑trans MK‑7. It is a genuine specification and a reasonable thing to look for. It is not, on its own, a reason to pay a large premium if a comparable product gives you the same micrograms for less.

Why D3 and K2 share a bottle

The pairing is now the default presentation. Applied Nutrition Vitamin D3 + Vitamin K2 is 90 capsules at £11.99; Combat Fuel High Strength Vitamin D3 and K2 is 90 capsules at £7.99; Allnutrition Vit D3 2000 + K2 is 60 capsules at £4.99; NXT Nutrition Vitamin D3 & K2 is 30 tablets at £5.99; Olimp Gold Vit D3+K2 is 60 capsules at £14.99.

When you compare these, compare both numbers. Products in this group vary widely on the D3 side — anywhere from 1,000 IU to 4,000 IU is common — while the K2 side may be 25mcg in one product and 100mcg in another at a similar price. It is entirely possible to buy the combination you wanted at the D3 strength you did not.

Remember too that UK labels quote vitamin D in both micrograms and international units: 25mcg equals 1,000 IU. If you already take a separate vitamin D supplement, a multivitamin or a cod liver oil, add up what you are getting in total before adding another. Our UK vitamin D guide covers the D3 side in detail.

The NRV percentage

UK labels express vitamin K against a Nutrient Reference Value of 75 micrograms. That single figure explains a lot of what you see on the shelf: a 45mcg product shows as 60% NRV, a 100mcg product as 133%, and a 5mg MK‑4 product as several thousand percent. The NRV is a labelling reference point used to make products comparable — it is not a target or a recommendation, and it is worth knowing simply so the percentages stop looking alarming.

Formats: it is not just capsules

K2 and D3+K2 are available across essentially every format, which means you can pick on preference rather than settling:

• Capsules — the most common, and usually the cheapest per serving.
• Tablets — Conteh Sports Vitamin D3 & K2 at 100 tablets for £11.10, Per4m D3 Plus K2 at 120 tablets for £14.99.
• Softgels — Chaos Crew Vitamin D3 + K2 at 90 softgels for £14.99, Allnutrition Omega 3, K2+D3 at 30 softgels for £5.99.
• Gummies — Nutriburst Vitamin D3 + K2 in lemon, 60 gummies at £14.99.
• Oral sprays — BetterYou DLux+ Vitamin D+K2 at 12ml for £8.99, Osavi Vitamin D3 + K2 Oral Spray at 25ml for £10.99, BetterYou Vitamin K2 Oral Spray at 25ml for £18.99.
• Liquids and drops — Marchon Supplements Vitamin D & K2 in peppermint, 15ml at £16.99, Vilgain Vitamin D3+K2 at 30ml for £14.99.

If you are weighing up which format suits you, our guide to choosing a supplement format covers what changes between them and how to work out cost per day.

One thing to check before you buy

Vitamin K interacts with some prescribed blood-thinning medication. If you take anything of that kind, speak to your GP or pharmacist before starting a vitamin K supplement — including the D3+K2 combinations, since the K2 is there whether you were shopping for it or not. This is the single most important check in the category and it takes one conversation.

A short buying checklist

1. Which form — MK‑7 (micrograms) or MK‑4 (milligrams)?
2. How many micrograms per serving, and how many units make that serving?
3. If it is a combination, what is the D3 figure in both mcg and IU?
4. Does anything else you take already contain vitamin K or vitamin D?
5. Cost per day, not price per pot.

Shop at NE Commerce

Standalone K2 and D3+K2 combinations sit across our Vitamins range, inside the wider Vitamins & Health section, in capsules, tablets, softgels, gummies and sprays.

A quick note

This article is general information, not medical or nutritional advice. Food supplements are not a substitute for a varied, balanced diet and a healthy lifestyle, and should not be used to prevent or treat any illness. Always read the product label, do your own research, and speak to a qualified doctor, pharmacist or registered nutritionist before starting a new supplement — especially if you are pregnant, breastfeeding, under 18, taking medication or managing a health condition.