In this comparison study, the bioavailability of MK-4 and MK-7 and subsequent changes in serum levels in healthy volunteers was examined in two separate experiments. MK-7 as low as 60 mcg resulted in measurable levels. Given that MK-4 still has a unique, rapid acting effect in up regulating osteocalcin and matrix GLA in addition to reducing inflammation and protecting the liver it is important to achieve adequate levels. Suggesting that 1500 μg MK-4/day was required to improve carboxylation.
Sato T, Schurgers LJ, Uenishi K. Comparison of menaquinone-4 and menaquinone-7 bioavailability in healthy women. Nutr J. 2012 Nov 12;11:93. doi: 10.1186/1475-2891-11-93. PMID: 23140417; PMCID: PMC3502319.