Global cardiovascular and bone health has been negatively impacted by widespread vitamin K2 deficiency and yet there is no established RDI (Recommended Daily Intake). NattoPharma and a team of researchers at Maastricht University (the Netherlands) are working together to establish an RDI for vitamin K2.
“The RDI for vitamin K is established based on coagulation factors only, but research continues to emerge that vitamin K and vitamin K-dependent proteins have physiological roles beyond coagulation,” said Leon Schurgers, professor of biochemistry of vascular calcification at Cardiovascular Research Institute at Maastricht University (CARIM). The AI (Adequate Intake) for vitamin K was established at 90 μg/day for women and 120 μg/day for men for the United States and Canada, and in Europe it is 1 μg/Kg/day. This was based on median phylloquinone (vitamin K1) intakes estimated from national surveys back in 2001.
“More recent research has confirmed different bioavailability/activity between K1 and K2, and additional biological functions of K2 due to different side chains,” said Schurgers. “Further, all epidemiological and interventional studies showed that only K2 was cardio-protective or has a beneficial effect on the arteries. This has not been considered in the forming of dietary recommendations.”
The Maastricht University team will be joined by the International Science and Health Foundation (ISHF), a research consortium responsible for the educational portal VitaminK2.org. According to Katarzyna Maresz, ISHF president, VitaminK2.org was specifically created to educate consumers and practitioners about the proven benefits of vitamin K2, recognizing the impact of widespread K2 deficiency. One of the first hurdles to overcome establishing an RDI is to have a biomarker or clinical endpoint that reflects the consequences of inadequate K2 consumption.
“Scientific knowledge has changed a lot recently, yet there is still a lack of suitable biomarkers or clinical endpoints that can be used to determine vitamin K2 requirements among adults,” said Maresz, offering that inactive Matrix Gla Protein (dpucMGP) or the ratio of inactive to inactive Osteocalcin (ucOC/cOC) could be used as markers of vitamin K status. “Given that some vitamin K deficiency or insufficiency has been seen in 97% of older subjects in a mixed population as reflected by their measures of dpucMGP, this could be a good starting marker. However, the ‘normal’ range should be established. Further, K1 influences these markers, too, and we have to consider the metabolic events such the inter-conversion of phylloquinone to MK-4.”
“We have been working with Maastricht University for almost two decades validating the health benefits of vitamin K2, creating this category,” said Eric Anderson, senior vice president of global marketing and business development with NattoPharma. “Our work, in addition to others’, is building that body of evidence. Now it is time to lead the way ensuring that a global recommendation exists so we can ensure vitamin K2 is adequately attained for the betterment of the world population—men and women, adults and children.”