Vitamin K2 Needs an RDI Separate from Vitamin K1

Nutrients. 2020 Jun 21;12(6):1852. doi: 10.3390/nu12061852.


Vitamin K and its essential role in coagulation (vitamin K [Koagulation]) have been well established and accepted the world over. Many countries have a Recommended Daily Intake (RDI) for vitamin K based on early research, and its necessary role in the activation of vitamin K-dependent coagulation proteins is known. In the past few decades, the role of vitamin K-dependent proteins in processes beyond coagulation has been discovered. Various isoforms of vitamin K have been identified, and vitamin K2 specifically has been highlighted for its long half-life and extrahepatic activity, whereas the dietary form vitamin K1 has a shorter half-life. In this review, we highlight the specific activity of vitamin K2 based upon proposed frameworks necessary for a bioactive substance to be recommended for an RDI. Vitamin K2 meets all these criteria and should be considered for a specific dietary recommendation intake.

Keywords: RDI; menaquinone; vitamin K; vitamin K-dependent proteins; vitamin K1; vitamin K2.

Publication types

  • Review

MeSH terms

  • Diet*
  • Dietary Supplements*
  • Humans
  • Recommended Dietary Allowances*
  • Vitamin K 1 / administration & dosage*
  • Vitamin K 1 / metabolism
  • Vitamin K 1 / pharmacokinetics
  • Vitamin K 2 / administration & dosage*
  • Vitamin K 2 / analogs & derivatives
  • Vitamin K 2 / metabolism
  • Vitamin K 2 / pharmacokinetics
  • Vitamin K 2 / therapeutic use
  • Vitamin K Deficiency / complications
  • Vitamin K Deficiency / metabolism
  • Vitamin K Deficiency / prevention & control


  • Vitamin K 2
  • Vitamin K 1
  • menaquinone 7