Prolonged Increase of Plasma Vitamin K2 Concentration by Natto (Bacillus subtilis natto) Ingestion

摘要

It was found that natto and/or natto bacillus contains a large amount of water-soluble vitamin K2, which is a complex form of protein and menaquinone-7, with pI of 3.0-4.0 and molecular weight of approximately 100,000. Also, revealed is that menaquinone-7 concentration in human plasma dramatically increases when natto and/or natto bacillus including a high concentration of water-soluble vitamin K2 is ingested. The effect of the increased concentration lasted very long periods of time. Menaquinone-7 concentration was more than twice as large (2.6+-0.9ng/ml plasma) as that for the value before ingestion, even 1 week after stopping the ingestion.