The Council for Responsible Nutrition (CRN) released its updated Vitamin K2 (menaquinone-7, MK-7) chapter as part of the Vitamin & Mineral Safety, 4th Edition (VMS4).

CRN’s safety evaluation established a supplemental highest observed intake (HOI) level of 375 µg/day for adults. The new guidance is for manufacturers, regulators and health practitioners seeking evidence-based recommendations for vitamin K2.

According to the association, previous CRN guidelines derived a single upper limit for vitamin K, comprising both K1 and K2. However, with the growing consumer interest and use of vitamin K2 supplements globally, a separate assessment was conducted on vitamin K2, specifically MK-7.

The new chapter reviews more than 40 human clinical trials conducted over the past decade on doses ranging from 58 to 462 µg/day for periods up to two years. Across the trials, no serious adverse effects related to MK-7 were observed and research showed no clinically meaningful impact on coagulation parameters in individuals not taking vitamin K antagonist (VKA) medications, such as Warfarin, the association explained.

Based on the analysis, CRN determined 375 µg/day as the HOI for supplemental MK-7 in adults. This HOI does not apply to those taking VKA anticoagulants—who should consult their health care providers before using vitamin K 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, 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.”

For more information, visit www.crnusa.org.