The Council for Responsible Nutrition establishes first-ever standalone safety guidance for vitamin K2 (MK-7) supplements, responding to rapidly expanding consumer demand for bone and cardiovascular health support.
CRN Publishes Dedicated Safety Assessment for Vitamin K2 MK-7
The Council for Responsible Nutrition Foundation (CRN) has released updated safety guidance establishing a Highest Observed Intake (HOI) level of 375 µg/day for vitamin K2 in the form of menaquinone-7 (MK-7) for adults. This marks a significant shift from previous editions of CRN’s Vitamin & Mineral Safety guidelines, which combined vitamin K1 and vitamin K2 into a single Upper Limit value.
The decision to provide separate assessment reflects the rapidly expanding global consumer interest in vitamin K2 supplements, driven by scientific evidence supporting MK-7’s role in bone and cardiovascular health. “CRN’s updated MK-7 chapter reflects our commitment to providing rigorous, transparent safety evaluations grounded in the totality of evidence,” explains Andrea Wong, senior vice president of 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 updated vitamin K2 guidance appears in the 4th edition of CRN’s Vitamin & Mineral Safety (VMS4), incorporating modern methodology, expanded human clinical evidence, and new global regulatory perspectives.
What Does “No Adverse Effects Observed” Mean for Supplement Manufacturers?
There is no established Tolerable Upper Intake Level (UL) for vitamin K (K1 or K2) by major bodies like EFSA (European Food Safety Authority) or the US NIH (National Institutes of Health) because no adverse effects or toxicity have been reported from high intakes in humans from food or supplements. Therefore, when a UL cannot be identified, the Highest Observed Intake (HOI) may be used as an alternative risk-assessment method.
The new guidance summarizes reviews of more than 40 human clinical trials conducted over the past decade, evaluating a wide range of vitamin K2 doses for periods up to two years. Among these trials, researchers observed no serious adverse effects related to MK-7 supplementation. Studies also consistently demonstrated no clinically meaningful impact on coagulation parameters in individuals not taking vitamin K-antagonist medications, commonly known as blood thinners such as warfarin.
Based on these findings, CRN established 375 µg/day as the HOI for supplemental MK-7 in adults. This guidance does not apply to individuals using VKA anticoagulants, who should consult their healthcare providers before using vitamin K-containing supplements.
Beyond Bone and Heart: Emerging Research Areas for Vitamin K2
While vitamin K2 is recognized for supporting bone density and cardiovascular wellness, scientific studies are highlighting additional potential benefitsResearch indicates that vitamin K2 may support metabolic health, help mitigate complications associated with impaired kidney function, and help address women’s health concerns during menopause, with emerging evidence also pointing to a role in brain health.
For manufacturers working with clinically studied vitamin K2 ingredients such as MenaQ7®, this comprehensive safety data provides evidence-based support for product development decisions. Dr. Katarzyna Maresz, coordinator of the Gnosis Vitamin K2 Scientific Advisory Committee, has noted that nearly two decades of clinical research support the safety of MenaQ7® in children and adults, including both healthy populations and individuals with underlying health conditions. She added that ongoing research—such as the VIKIPEDIA study, which is evaluating intakes up to 1,000 µg/day—may justify future upward revisions of the HOI as additional data become available.
The CRN’s dedicated assessment of vitamin K2 MK-7 offers the supplement industry transparent, science-backed guidance for formulating products that meet consumer demand while maintaining the highest safety standards.