What it is
Regulatory status: essential nutrient and dietary supplement ingredient; no separate US recommended intake for K2 forms
Mechanism evidence: human
At a glance
What it is, why people use it, the evidence, and what to know before trying it.
Why people use it
- Vitamin K adequacy
- Bone health
- Cardiovascular support
Evidence at a glance
Vitamin K is essential, but the evidence does not support treating an unspecified K2 product as a proven cardiovascular or bone intervention. Form, dose, diet and anticoagulant use are critical context.
Confidence: weak
Safety & interactions
Known side effects, interactions and use limits from reviewed sources.
Vitamin K has a major interaction with warfarin and similar vitamin-K antagonists; large intake changes can alter anticoagulation. Safety and dose interpretation depend on whether the product is MK-4, MK-7 or a blend.
- Use with vitamin-K antagonist therapy unless coordinated with the prescribing clinician
- Warfarin and other vitamin-K antagonist anticoagulants
Forms and variants
This review does not automatically apply to:
- vitamin K1 or phylloquinone assumed equivalent
- unspecified vitamin D and K blends
Seen in protocols
Public protocols that include Vitamin K2. Open one to see the full context and source.