Natto-Derived Menaquinone Outperforms Synthetic Vitamin K1 in Trials
Natto is a Japanese food made from fermented soybeans that is rich in the naturally occurring vitamin K2 menaquinone-7 (MK-7). Both vitamin K1 and MK-7 have been found to slow bone loss and improve bone mineral density—but new research is showing that MK-7 may have an edge.
One set of four clinical trials5 compared the bioavailability, dose-response relationship, level of osteocalcin carboxylation, and interference with anticoagulants in response to vitamin K1 and MK-7 supplementation. While both ingredients induced osteocalcin carboxylation within three days, only MK-7 increased that effect over time; the effect of vitamin K1 plateaued only barely above placebo.