Menaquinone-4 versus Menaquinone-7 Menaquinone-4 (MK-4) Menaquinone-7 (MK-7) Source Synthetic Natural (natto) Recommended dosage 45 milligrams (4,500 micrograms) 120 micrograms or more Dosing frequency Divided dose, three times daily Once daily Half-life in body A few hours, hence the need for frequent doses A few days, so a one-a-day dose is fine Health Canada allowable dosage Therapeutic dose of this form exceeds allowable dosage for Canada, suitable for United States only Therapeutic dose within Health Canada limits of 120 micrograms
