WASHINGTON, D.C.—The CRN Foundation today announced the release of CRN’s updated Vitamin K2 (menaquinone-7, MK-7) chapter as part of the Vitamin & Mineral Safety, 4th Edition (VMS4). For the first time, CRN’s rigorous safety evaluation establishes a supplemental Highest Observed Intake (HOI) level of 375 µg/day for adults, offering essential new guidance for manufacturers, regulators, and health practitioners seeking evidence-based recommendations for this increasingly used nutrient.
Previous editions of CRN’s Vitamin & Mineral Safety derived a single UL (upper limit) value for vitamin K, encompassing vitamin K1 and vitamin K2. Given the rapidly expanding consumer interest and use of vitamin K2 supplements worldwide, a separate assessment was conducted for vitamin K2, specifically MK-7, which is widely recognized for its role in supporting bone and cardiovascular health.
Robust Clinical Data Support MK-7 Safety
The new chapter reviews more than 40 human clinical trials conducted over the past decade, evaluating doses ranging from 58 to 462 µg/day for periods up to two years.
Across these trials, no serious adverse effects related to MK-7 were observed, and research consistently demonstrated no clinically meaningful impact on coagulation parameters in individuals not taking vitamin K antagonist (VKA) medications such as warfarin.
Based on these findings, CRN identified 375 µg/day as the HOI for supplemental MK-7 in adults. This HOI does not apply to individuals using VKA anticoagulants, who should consult their healthcare providers before using vitamin K–containing supplements.
A Milestone in Nutrient Safety Science
“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, scientific and regulatory affairs at CRN. “Establishing a HOI for Vitamin K2 (MK-7) represents a major step forward for scientific understanding and responsible product development across the dietary supplement category.”
The MK-7 chapter is part of CRN’s ongoing rollout of updated nutrient safety assessments within Vitamin & Mineral Safety, 4th Edition, which incorporates modern methodology, expanded human clinical evidence, and new global regulatory perspectives. VMS4 is funded through a grant from the CRN Foundation, which provides information and education about the beneficial, safe, and responsible use of dietary supplements and their ingredients as part of a healthy lifestyle.
Availability
The Vitamin K2 (MK-7) chapter is now available to the public.
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About the CRN Foundation
The CRN Foundation is a 501(c)(3) nonprofit organization that provides consumers and healthcare practitioners with science-based information on the benefits of dietary supplements and functional food. Through education and outreach initiatives, the Foundation promotes responsible use of nutritional products to improve public health and wellness.