December 27, 2025

Vitamin K2 Safety: CRN Sets Highest Observed Intake (HOI) Level for MK-7 Supplements

CRN’s updated Vitamin K2 chapter confirms MK-7 supplements are safe at intakes up to 375 µg/day, based on decades of research and clinical trials.

Updated Vitamin K2 Safety Research

As consumer interest in Vitamin K2 continues to rise, safety remains a top priority. The Council for Responsible Nutrition (CRN) has published its updated Vitamin K2 chapter in Vitamin & Mineral Safety, 4th Edition. For the first time, CRN establishes a Highest Observed Intake (HOI) level for MK-7 supplements, providing essential guidance for the industry.

What is a Highest Observable Intake?

The Highest Observable Intake or HOI is a key dietary risk assessment metric that identifies the highest intake level of a nutrient shown to be safe, even when no adverse effects have been documented. This milestone provides the industry with a science-backed framework to ensure product safety and consumer confidence.

What Is the New HOI for Vitamin K2?

CRN identifies 375 µg/day as the highest observable intake (HOI) for supplemental MK-7 in adults. This level is based on robust clinical data and does not apply to individuals taking vitamin K anticoagulant medications.

How Was the Vitamin K2 HOI Determined?

The updated chapter reviews more than 40 human clinical trials, with doses ranging from 58 to 462 µg/day for up to two years. Across these studies, no serious adverse effects were reported, and MK-7 showed no clinically meaningful impact on coagulation parameters in healthy individuals.

Why Is a New HOI Important for the Industry?

Establishing an HOI for MK-7 represents a major step forward for scientific understanding and responsible product development. It provides manufacturers, regulators, and health practitioners with evidence-based recommendations for this increasingly popular nutrient.