Ultra K2 Menaquinone-4 from Klaire Labs/SFI Health delivers vitamin K2 in the MK-4 form (menatetrenone), a short-chain menaquinone naturally present in animal tissues and known for its role in supporting calcium metabolism, bone mineral density, and cardiovascular health. Formulated for practitioners and clinically aware individuals seeking targeted K2 supplementation.
Why It's Worth Considering: Klaire Labs applies pharmaceutical-grade manufacturing standards to this MK-4 formulation, providing a clean, hypoallergenic base consistent with their practitioner-line quality standards.
Vitamin K1 (phylloquinone) is for blood clotting — abundant in leafy greens. Vitamin K2 (menaquinone) directs calcium metabolism — puts calcium in bones and keeps it out of arteries. Most people get enough K1 from diet but are deficient in K2, which is found mainly in fermented foods (natto, certain cheeses) and animal liver.
MK-7 is the most bioavailable and longest-acting form of K2, with a half-life of ~3 days (vs ~1 hour for MK-4). This means a single daily dose maintains therapeutic blood levels 24/7. MK-7 is derived from natto (fermented soybeans) and has the strongest clinical evidence for bone density and arterial health.
For general health with D3: 100-200mcg MK-7 daily. For osteoporosis: 180-360mcg. For cardiovascular calcification prevention: 180-200mcg. The dose should scale with your D3 intake — higher D3 doses require more K2 to handle the increased calcium absorption.
If you're on warfarin/Coumadin: NO — K2 counteracts warfarin and will destabilize your INR. Consult your cardiologist. If you're on newer anticoagulants (Eliquis/apixaban, Xarelto/rivaroxaban, Pradaxa/dabigatran): these are NOT vitamin K-dependent, so K2 is safe. Always confirm with your prescribing physician.
Ask Gabriel for personalized stacking recommendations.
No significant interactions identified. Always consult your healthcare provider.
† These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.
