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Natto / Vitamin K2 (for Arteries) supplement
Enzyme / Vitamin

Natto / Vitamin K2 (for Arteries): Benefits, Dosage, Forms & Research

Enzyme / Vitamin

This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer

TL;DR — Quick Answer

Vitamin K2 (MK-7) activates proteins that prevent calcium from depositing in arteries, while nattokinase is a fibrinolytic enzyme that supports healthy blood flow. Together, they address arterial calcification and blood viscosity. Standard dosing is 100-200mcg K2 (MK-7) and/or 2000 FU nattokinase daily.

Key Facts

What it is
Vitamin K2 (MK-7) activates anti-calcification proteins; nattokinase is a fibrinolytic enzyme from fermented soy
Primary benefits
  • Reduces arterial calcification (K2/MK-7)
  • Supports healthy blood clot breakdown (nattokinase)
  • Directs calcium to bones, away from arteries
  • Improves arterial elasticity and stiffness
  • May reduce cardiovascular mortality risk
Typical dosage
100-200mcg vitamin K2 (MK-7) daily; 2000 FU nattokinase daily
Evidence level
Moderate
Safety profile
Safe with Caution

What the Research Says

The cardiovascular role of vitamin K2 has been established through epidemiological and interventional studies. Geleijnse et al. (2004) reported the landmark Rotterdam Study finding that high K2 intake reduced coronary heart disease mortality by 57%. Knapen et al. (2015) provided interventional evidence that MK-7 supplementation improves arterial stiffness over 3 years. For nattokinase, Kurosawa et al. (2015) demonstrated fibrinolytic and anticoagulant effects in a well-designed RCT. The key distinction is that K2 addresses calcification (long-term structural protection) while nattokinase addresses clot dynamics (blood flow). Both components are complementary for comprehensive arterial health.

Benefits of Natto / Vitamin K2 (for Arteries)

  • Arterial calcification prevention — Knapen et al. (2015) found that 180mcg MK-7 daily for 3 years significantly improved arterial stiffness (carotid-femoral pulse wave velocity) in healthy postmenopausal women compared to placebo.
  • Cardiovascular mortality reduction — the Rotterdam Study (Geleijnse et al., 2004, n=4,807) found that high dietary vitamin K2 intake was associated with a 57% reduction in coronary heart disease mortality over 7-10 years.
  • Fibrinolytic activity — Kurosawa et al. (2015) demonstrated that nattokinase (2000 FU/day) reduced fibrinogen levels and factor VIII activity, supporting healthy clot breakdown in a randomized trial.
  • Calcium metabolism — K2 activates matrix Gla protein (MGP) and osteocalcin, creating a dual mechanism that removes calcium from arterial walls and deposits it in bone matrix.
Did you know?

The cardiovascular role of vitamin K2 has been established through epidemiological and interventional studies.

Forms of Natto / Vitamin K2 (for Arteries)

FormBioavailabilityBest For
MK-7 (Menaquinone-7) CapsulesHighBest form for arteries — longest half-life (~72 hours), ensures consistent MGP activation with once-daily dosing
MK-4 (Menaquinone-4) CapsulesLow (short half-life)Bone-focused — requires 3x daily dosing (half-life ~6 hours); less practical for arterial health
Nattokinase Capsules (2000 FU)ModerateBlood flow support — standardized fibrinolytic enzyme units; separate from vitamin K2 content

Dosage Recommendations

General recommendation: 100-200mcg vitamin K2 (MK-7) daily; nattokinase 2000 FU daily if desired

Timing: Take K2 with a fat-containing meal; nattokinase can be taken on an empty stomach • Take with food for best absorption.

Dosage by Condition

ConditionRecommended DoseEvidence
Arterial calcification prevention180-200mcg MK-7 dailyModerate
Arterial stiffness180mcg MK-7 daily for 3+ yearsModerate
Blood flow support2000-4000 FU nattokinase dailyModerate
General cardiovascular maintenance100mcg MK-7 dailyModerate

Upper limit: 360mcg MK-7/day; 4000 FU nattokinase/day

Side Effects and Safety

Safety profile: Safe with Caution

Potential Side Effects

  • Generally very well-tolerated at recommended doses
  • Mild GI discomfort (rare)
  • Nattokinase: increased bleeding risk in susceptible individuals
  • Allergic reaction in those with soy allergy (nattokinase derived from soy)

Drug & Supplement Interactions

  • Warfarin/vitamin K antagonists — K2 directly opposes warfarin mechanism; do NOT combine without medical supervision
  • Anticoagulants and antiplatelets — nattokinase may increase bleeding risk
  • Vitamin D — synergistic for calcium metabolism; often taken together beneficially
Check Natto / Vitamin K2 (for Arteries) interactions with other supplements →
BenefitsDosage GuideSide EffectsTypes & FormsResearchFAQ

Related Conditions

Heart Health

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Frequently Asked Questions

Can I take vitamin K2 if I am on blood thinners?

If you take warfarin or another vitamin K antagonist, do NOT take supplemental K2 without your doctor's explicit guidance. Vitamin K2 activates clotting factors that warfarin is designed to inhibit. However, some practitioners do use stable, low-dose K2 alongside warfarin with careful INR monitoring. If you take DOACs (like rivaroxaban or apixaban), K2 is generally safe since these drugs do not work through vitamin K pathways. Always consult your prescriber.

What is the difference between MK-4 and MK-7?

Both are forms of vitamin K2 but differ significantly. MK-7 (from natto) has a long half-life (~72 hours), allowing once-daily dosing and sustained blood levels. MK-4 has a very short half-life (~6 hours) and requires dosing 3 times daily. For arterial health, MK-7 is preferred because it maintains consistent activation of matrix Gla protein (the anti-calcification enzyme). MK-4 is primarily studied for bone health at high doses (45mg/day) in Japan.

Is nattokinase the same as vitamin K2?

No, they are completely different compounds that both happen to come from natto (fermented soybeans). Nattokinase is a fibrinolytic enzyme that helps break down fibrin in blood clots, supporting healthy blood flow. Vitamin K2 (MK-7) is a fat-soluble vitamin that activates proteins preventing arterial calcification. Many natto-derived supplements contain both, but they should be evaluated separately. Some nattokinase products are specifically processed to remove vitamin K2, making them safer for warfarin users.

References

  1. (). Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomised clinical trial. Thrombosis and Haemostasis. DOI
  2. (). Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. Journal of Nutrition. DOI
  3. (). A single-dose of oral nattokinase potentiates thrombolysis and anti-coagulation profiles. Scientific Reports. DOI