Safety Profile
Overall safety rating: Safe with Caution
Natto / Vitamin K2 (for Arteries) Side Effects & Safety
This content is for informational purposes only and does not constitute medical advice. Consult your healthcare provider before starting any supplement. Full disclaimer
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
Maximum Dose
Do not exceed: 360mcg MK-7/day; 4000 FU nattokinase/day
References
- Knapen MH, Braam LA, Drummen NE, Bekers O, Hoeks AP, Vermeer C (2015). Menaquinone-7 supplementation improves arterial stiffness in healthy postmenopausal women. A double-blind randomised clinical trial. Thrombosis and Haemostasis. DOI PubMed
- Geleijnse JM, Vermeer C, Grobbee DE, Schurgers LJ, Knapen MH, van der Meer IM, Hofman A, Witteman JC (2004). Dietary intake of menaquinone is associated with a reduced risk of coronary heart disease: the Rotterdam Study. Journal of Nutrition. DOI PubMed
- Kurosawa Y, Nirengi S, Homma T, Esaki K, Ohta M, Clark JF, Hamaoka T (2015). A single-dose of oral nattokinase potentiates thrombolysis and anti-coagulation profiles. Scientific Reports. DOI PubMed