Vitamin K2 from Natto

A highly bioactive form of Vitamin K2, essential for directing calcium to bones and away from arteries.

Also known as: Menaquinone-7 • MK-7

other Names
MK-7, Menaquinone-7
primary Benefits
Supports bone health, promotes cardiovascular health by reducing arterial calcification.
common Dose
90-180 mcg per day
best Form
MK-7 from natto or synthesis
timing
With a meal containing fat.
safety Rating
Very safe, with no known toxicity.

Overview

Vitamin K2 as Menaquinone-7 (MK-7) is a fat-soluble vitamin most famously found in high concentrations in natto, a traditional Japanese fermented soybean dish. Its primary role is to activate proteins that regulate calcium metabolism. It activates osteocalcin, which helps bind calcium to the bone matrix, and matrix Gla protein (MGP), which helps prevent calcium from depositing in arteries and soft tissues. This dual action makes it critical for both skeletal and cardiovascular health.

Key Benefits

Promotes Bone Health

Activates osteocalcin, a protein that helps incorporate calcium into bones, improving bone density and strength.

Supports Cardiovascular Health

Activates Matrix Gla Protein (MGP) which inhibits calcium from being deposited in artery walls, helping to maintain arterial flexibility.

Improves Dental Health

Osteocalcin, activated by K2, is also involved in stimulating the growth of new dentin, the calcified tissue underneath tooth enamel.

Dosage & How to Take

A daily dose of 90-180 mcg is commonly used for general health.

PurposeDoseNotes
Bone Support180-360 mcg/dayOften combined with Vitamin D3.
Cardiovascular Support90-180 mcg/dayLong-term supplementation is key.

Best Time to Take

Take with a meal containing fat to enhance absorption.

With or Without Food

Yes, it is a fat-soluble vitamin.

Forms & Bioavailability

FormAbsorptionBest ForNotes
Menaquinone-7 (MK-7)HighBone and cardiovascular healthHas a longer half-life than MK-4, allowing for once-daily dosing.
Menaquinone-4 (MK-4)LowerMore researched for specific bone density applicationsHas a very short half-life, requiring multiple doses per day.

Side Effects & Safety

Common

    Rare

      Contraindications

      • Concurrent use with warfarin (Coumadin) unless directed by a doctor.

      Interactions

      Warfarin (Coumadin)High

      Vitamin K directly counteracts the effect of warfarin, reducing its anticoagulant efficacy.

      Scientific Research

      2013Osteoporosis International

      Three-year low-dose menaquinone-7 supplementation helps decrease bone loss in healthy postmenopausal women

      MK-7 supplementation significantly improved vitamin K status and decreased the age-related decline in bone mineral density.

      Food Sources

      Natto (fermented soybeans)
      Hard cheeses (Gouda, Brie)
      Egg yolks
      Butter

      Frequently Asked Questions

      Medical Disclaimer

      This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.