WASHINGTON — The CRN Foundation has issued an updated safety assessment for vitamin K2, confirming strong evidence of the nutrient’s safety and establishing a new supplemental Highest Observed Intake level for menaquinone-7 (MK-7).
The updated chapter, part of CRN’s Vitamin & Mineral Safety, 4th Edition, establishes a supplemental HOI of 375 micrograms per day for adults, marking the first time CRN has provided a specific intake level for MK-7. The new assessment comes amid rapidly increasing consumer interest in vitamin K2, which is widely used for bone and heart health support.
Earlier editions of the reference grouped vitamin K1 and K2 under a single upper limit. With the increased use of K2 supplements worldwide, CRN conducted a separate review focused specifically on MK-7.
The updated safety assessment reviewed over 40 human clinical trials from the past decade. These studies assessed doses ranging from 58 to 462 micrograms daily for up to two years. CRN reported no serious adverse effects associated with MK-7 and found no significant effects on coagulation in people not using vitamin K antagonist medications like warfarin.
Based on that body of evidence, CRN identified 375 micrograms per day as the HOI for supplemental MK-7 in adults. The organization emphasized that the guidance does not apply to individuals taking VKA anticoagulants, who should consult healthcare providers before taking vitamin K-containing supplements.
“CRN’s updated MK-7 chapter reflects our commitment to providing rigorous, transparent safety evaluations grounded in the totality of evidence,” said Andrea Wong, senior vice president of scientific and regulatory affairs at CRN. “Establishing a HOI for vitamin K2 represents a major step forward for scientific understanding and responsible product development across the dietary supplement category.”
The updated MK-7 chapter is part of CRN’s larger effort to update nutrient safety evaluations within Vitamin & Mineral Safety, 4th Edition. The volume uses current scientific methods, more clinical evidence, and global regulatory views. The project is funded by the CRN Foundation, a nonprofit dedicated to providing science-based information on the responsible use of dietary supplements.
The Vitamin K2 (MK-7) chapter is now available to the public.
