Vitamin K2: MK-7 vs MK-4, pairing it with D3 and calcium, and how to choose

Vitamin K2 is the form of vitamin K people usually mean when they talk about bones and calcium, and it's most often sold alongside vitamin D3. This guide explains K1 vs K2, MK-7 vs MK-4, food sources, how K2 pairs with D3 and calcium, and how to read the bottle, with the K2 supplements we carry.

On our shelf you'll find vitamin K2 on its own, D3 and K2 together, and bone formulas that add calcium and magnesium, in capsules, softgels, drops and liquids. It's written for anyone who already takes vitamin D, eats little natto, cheese or other fermented foods, or is putting together a bone health routine. If you're not sure which fits, bring your current vitamin D to the supplement aisle at either store and we'll help you match it.

What is vitamin K2?

Vitamin K is a fat-soluble vitamin, and it comes in two natural families. Vitamin K1 (phylloquinone) is the one in green leafy vegetables, and the body uses it mainly for normal blood clotting. Vitamin K2 (menaquinones) is found in fermented foods and some animal products, and small amounts are made by bacteria in the gut.

Both forms activate vitamin K dependent proteins. The ones people talk about with K2 are osteocalcin, a protein that helps bind calcium into bone, and matrix Gla protein, which works in blood vessels and other soft tissues. Through them, vitamin K plays a critical role in blood coagulation and a part in bone metabolism, bone mineralization and calcium metabolism. That's why vitamin K2 is described as helping the body use calcium and helping maintain bone health, and why it's so often paired with vitamin D.

Vitamin D helps you absorb calcium; vitamin K2 helps your body put it to use.

Vitamin K1 vs K2: blood clotting and bones

K1 is cleared from the blood fairly quickly, while MK-7 stays in circulation much longer. That longer half-life is why most K2 supplements use MK-7 at around 100 to 120 mcg, while MK-4 is often used in larger amounts. A few, such as AOR Vitamin K2, give you both.

Food sources of vitamin K2

Most dietary vitamin K intake in western diets is K1 from vegetables. Vitamin K2 is harder to come by, and how much you get depends on how often you eat fermented foods and certain animal products.

• Natto. This Japanese dish of fermented soybeans is the richest food source of K2 by far and one of the few plant sources. It's also where much of the MK-7 in supplements comes from.
• Aged and hard cheeses. Fermentation adds K2; amounts vary by cheese.
• Egg yolks, butter and organ meats such as liver, mainly as MK-4.
• Other fermented foods, like sauerkraut, in smaller amounts.

Leafy greens are still worth eating for K1, and a heart healthy diet full of vegetables covers a lot of ground. If you don't eat natto or much cheese, a supplement is a simple way to get vitamin K2 without changing your plate. Our beef liver guide covers organ meats in capsule form.

Do you need to take K2 with D3?

You don't have to, but the two are a natural pair and most people buy them together. Vitamin D helps the body absorb calcium from food; vitamin K2 helps direct that calcium to bones and teeth. Through an Atlantic Canadian winter, when many of us take vitamin D every day, a combined D3 and K2 product saves a bottle. Our vitamin D winter guide covers the D side in more depth.

Combined products come in three main shapes:

• Drops. CanPrev D3 & K2 Drops give 250 IU of D3 and 30 mcg of K2 per drop, in MCT oil, so it's easy to adjust. Naka Bioactive D3 + K2 drops give 2500 IU of D3 and 120 mcg of MK-7 from natto in four drops.
• Softgels. CanPrev D3 & K2 softgels use organic coconut oil, and Natural Factors Vitamin K & D pairs 120 mcg of MK-7 from natto with 1000 IU of D3.
• Vegan capsules. Naka Vegan D3 + K2 pairs 1000 IU of vegan D3 with 120 mcg of K2 in a vegetable capsule.

Vitamin K2 on its own

Single K2 is handy if you already like your vitamin D, take a multi with D, or want to set the amounts separately. Most are 100 to 120 mcg of MK-7 per capsule or softgel, taken once a day.

• Naka Platinum K2 MK-7: 100 mcg of natto-derived MK-7 in a vegetable capsule, one a day, in 150 or 300 capsule bottles. No added gluten, dairy or animal products.
• CanPrev Vitamin K2: 120 mcg of MK-7 in organic coconut oil. CanPrev's K2 is made by a soy-free, plant-based synthesis.
• AOR Vitamin K2: 120 mcg per capsule, split 60 mcg MK-4 and 60 mcg MK-7, for people who want both forms.
• Natural Factors and Preferred Nutrition: 100 mcg of MK-7 in a vegetable capsule, the simple everyday option.
• CanPrev K2 Drops: 30 mcg of MK-7 per drop in MCT oil, for anyone who already takes a D3 drop and wants to add K2 separately.

Preferred NutritionVitamin K2 100 mcgMK-7, the long-lasting form of K2. 60 vegetable capsules.Shop →

Pairing K2 with calcium and magnesium for strong bones

Bone health is a team effort: calcium is the building material, vitamin D helps you absorb it, vitamin K2 helps put it in place, and magnesium plays a part too. Some people take each separately; others prefer one formula that covers several.

If you'd rather keep calcium separate, CanPrev Calcium Bis-Glycinate gives 200 mg of elemental calcium per vegetable capsule, and Naka Coral Calcium gives 225 mg of calcium with 125 mg of magnesium and a little vitamin D3. For a liquid, Naka Bioactive Cal/Mag + K2 combines calcium, magnesium, D3 and K2 with collagen, zinc and boron in a berry flavour. Our magnesium guide explains the forms.

How to read a vitamin K2 label

1. Find the form. The medicinal ingredients list vitamin K2 as menaquinone-7 (MK-7) or menaquinone-4 (MK-4), and sometimes the source, such as natto or a plant-based synthesis.
2. Check the amount. K2 is measured in micrograms (mcg). Most MK-7 products sit at 100 to 120 mcg per capsule; drops list it per drop.
3. Look at the partners. If it's a combination, note the vitamin D3 amount in IU and whether the D3 is vegan (from lichen) or from lanolin.
4. Read the base and capsule. Oils like MCT or coconut help a fat-soluble vitamin absorb. Softgels are often gelatin; vegetable capsules suit vegetarians. Look for soy free if you avoid soy, since natto is a soy food.
5. Read the directions and cautions. Most are one a day; follow the label. Every vitamin K label carries a caution for people who take blood thinners such as warfarin, because vitamin K and those medications act on the same clotting system. Read it before you start.
6. Look for the NPN. An eight-digit NPN shows the product is licensed for sale in Canada.

Vitamin K2 health benefits, in plain label terms

People most often take vitamin K2 to support bone health, usually alongside vitamin D and calcium, and because they don't eat many K2-rich foods. Many older adults add it to the vitamin D they already take. On Canadian labels you'll see claims such as "helps maintain bone health", "helps in the development and maintenance of bones and teeth" and "helps support normal blood clotting". Vitamin K2's role in calcium metabolism is also why it comes up in conversations about cardiovascular health; that's an area where research is ongoing, and the claims on our bottles stay with bones, teeth and clotting.

Questions we get a lot

What is vitamin K2 taken for?

Mostly for bone health, alongside vitamin D and calcium. K2 helps the body use calcium and helps maintain bones and teeth, and vitamin K as a whole supports normal blood clotting.

Which foods are high in vitamin K2?

Natto is the richest by a long way. Aged and hard cheeses, egg yolks, butter, organ meats such as liver, and fermented foods like sauerkraut also supply some. Leafy greens are rich in vitamin K1 rather than K2.

Is MK-7 or MK-4 better?

They're both natural forms of K2. MK-7 stays in the body longer, so it works at around 100 mcg a day and is the most common form on the shelf. MK-4 is cleared faster, so it's often used in larger amounts. If you can't decide, AOR Vitamin K2 contains both.

Can I take vitamin K2 every day?

Yes, K2 supplements are made to be taken daily, usually one capsule or softgel. Follow the directions on your bottle.

Is vitamin K2 deficiency common?

Low vitamin K overall is uncommon in healthy adults, because most people get enough vitamin K1 from vegetables. Vitamin K2 intake is a different story: it simply depends on how much fermented food, cheese and egg yolk you eat, and many people eat very little.

Is there a vegan vitamin K2?

Yes. MK-7 from natto or plant-based synthesis is vegan, so look at the capsule. Naka Platinum K2 and Naka Vegan D3 + K2 come in vegetable capsules, and SUKU Vitamins' D3, K2 and B12 gummy uses vegan D3 from lichen.

When is the best time to take K2?

With a meal that contains some fat, since K2 is fat-soluble. Many people take it with their vitamin D at breakfast or dinner, often next to the eggs or cheese that bring a little dietary vitamin K2 of their own.

Shop vitamin K2 in Bedford, Dartmouth or online

You'll find vitamin K2 with our bone and teeth health supplements and in vitamins and minerals A to Z, at both stores: 486 Starboard Drive in Bedford and 590 Portland Street in Dartmouth, open seven days. In HRM, order by 11 am with Luminate Express for same-day delivery, or choose pickup. Anywhere else in Canada, orders over $80 ship free. Many women's multis include K2 as well; our women's multivitamin guide shows which.

Sources: product labels and listings for the items shown. This article is general information, not medical advice.