Vitamin K2? Ensure the balance between MK-4 and MK-7
Discover everything about vitamin K2, the difference between MK-4 and MK-7, and why the right balance is so important for your bones, blood vessels and calcium regulation.
What is vitamin K2? | How is K2 different from K1? | Why are K2 supplements combined with D3? | Where is vitamin K2 found in food? | What makes a good vitamin K2 supplement? | About NoordCode Ultimate D3 + K2
If there's one vitamin worth knowing more about, it's vitamin K2. Often overlooked in favour of the better-known K1, vitamin K2 tends to be underrepresented in conversations about health.
With a balanced diet rich in green vegetables, you're likely to get enough vitamin K1. That's why this article focuses on vitamin K2—where to find it in your diet, the difference between its two forms (MK-4 and MK-7), what roles they play in the body, and why NoordCode Ultimate D3 + K2 includes both forms in a 1:1 ratio.
What is vitamin K2?
Vitamin K2 is a fat-soluble vitamin that contributes to normal blood clotting and helps maintain strong bones. Scientific literature also highlights the role of vitamin K2 in regulating calcium in the body.
What does vitamin K2 do in your body?
- Supports the skeletal system
- Contributes to the maintenance of strong bones
- Helps with mineral absorption in bone tissue
- Is important for bone composition
- Plays a role in bone formation
- Supports healthy blood clotting
How is Vitamin K1 different from K1?
Vitamin K comes in two main forms: K1 (phylloquinone) and K2 (menaquinones). K1 is mainly found in leafy green vegetables, and with a varied diet, you're likely to consume enough of it without supplementation.
K2 is a different story. It is found in animal products and fermented foods.
Why are K2 supplements combined with D3?
Vitamin K2 supplements are often paired with D3. That's because vitamins D and K work closely together:
- Vitamin D helps your body absorb calcium from food
- Vitamin K helps direct calcium into your bones
Together, they support:
- Strong bones: calcium is absorbed and stored efficiently
- Healthy blood vessels: reduced risk of calcification
- Blood clotting: contributes to normal clotting function
- Stable calcium levels in blood and tissues
Want to know more? Check our ultimate D3 + K2 formula explained.
Where is vitamin K2 found in food?
Vitamin K2 exists in five different forms, with MK-4 and MK-7 being the most important to focus on. Both are found in animal products and fermented foods.
Sources of MK-4:
- Egg yolk
- Liver, especially duck liver
- Butter from grass-fed cows
- Full-fat dairy products
Sources of MK-7:
- Natto (fermented soybeans – highest content)
- Raw milk and fermented cheeses
- Sauerkraut and kimchi (in smaller amounts)
In a typical Western diet, MK-4 and MK-7 are not commonly consumed together. Natto is rarely eaten, and organ meats and fermented cheeses are usually consumed in moderation. In this case, a supplement can be a valuable addition to a healthy, varied diet.
What is the difference between MK-4 and MK-7?
The two main forms of vitamin K2, MK-4 and MK-7, differ in origin, function and how they work in the body. This is why they complement each other well. A natural 1:1 ratio provides both quick absorption and long-lasting effect.
| MK-4 | MK-7 |
| Found in animal products (egg yolk, liver) | Found in fermented foods (such as natto, cheese) |
| Absorbed quickly | Absorbed more slowly |
| Distributes through tissues like brain and organs | Remains in the bloodstream for longer |
| Short-acting | Supports long-term bone and vascular health |
Regional differences
Available sources and research into the different forms of K2 vary significantly by region:
In the Netherlands, much research has been done into the effects of MK-7 (at 90–180 mcg per day), largely due to the role of cheese and natto in the diet.
In Japan, fermented foods play a more central role. There, decades of research have focused on high-dose MK-4 (up to 45 mg per day) as a therapy for osteoporosis.
The NoordCode formula brings these insights together: 100 mcg MK-4 + 100 mcg MK-7, so you benefit from the fast absorption of MK-4 and the sustained action of MK-7.
What makes a good vitamin K2 supplement?
If you're considering supplementing your diet with extra vitamin K2, look for the following:
- Contains both MK-4 and MK-7 in equal ratio
- Natural forms such as MenaQ7®
- Fat-soluble base such as olive oil
- Dark glass packaging with antioxidant protection
- Dropper system for easy dosing
When is the best time to take vitamin K2?
Take your supplement with a fat-containing meal. Both D3 and K2 are better absorbed with fat. Morning or early afternoon intake is often preferred.
About NoordCode Ultimate D3 + K2
NoordCode Ultimate D3+K2 combines 100 mcg MK-4 and 100 mcg MK-7 (MenaQ7®) in a 1:1 ratio. This combination gives you the best of both worlds: rapid absorption and long-lasting support.
- 100 mcg MK-4 + 100 mcg MK-7 (MenaQ7®)
- 75 mcg vitamin D3 from lanolin
- Ratio designed for optimal calcium distribution
- Olive oil as a carrier for better absorption
- Liquid format with dropper
- Packaged in dark glass, protected with rosemary extract
