What is it?
Vitamin K is a form-dependent nutrient family
1Vitamin K includes phylloquinone (K1) and menaquinones (K2), including MK-7. Product labels can differ by form, concentration, and serving amount, so K1 bulk powders and K2 capsules or powders are not automatically like-for-like.
Names, aliases and forms
Mechanisms of action
Vitamin-K-dependent protein activation
1Vitamin K is a coenzyme for a carboxylase involved in making vitamin-K-dependent proteins, including proteins in normal blood-clotting biology. This essential function does not demonstrate a same-day nootropic effect.
Potential effects and evidence map
Vitamin K is essential for vitamin-K-dependent protein activation, including normal blood-clotting biology. K1 and K2 forms should not be assumed to be interchangeable shopper units. A review of the cognition literature describes associations as interesting but not definitive, so current evidence does not establish vitamin K supplementation as a focus, memory, or mental-energy enhancement strategy.
Current clinical literature does not establish vitamin K supplements as an acute focus or attention enhancer.
Typical dosages and timing
The U.S. Adequate Intake is 90 mcg/day for adult women and 120 mcg/day for adult men. This is a nutrient-reference context, not a universal dose recommendation for every K1 or K2 product or a reason to change an anticoagulant-managed routine.
Safety, side effects and risk profile
Warfarin and similar vitamin-K-antagonist anticoagulants require a consistent vitamin K intake from food and supplements; do not make sudden changes without clinician guidance.
Interactions and cautions
Warfarin, phenprocoumon, acenocoumarol, and tioclomarol antagonize vitamin K activity. Sudden changes in vitamin K intake can alter anticoagulant effects, so any supplement change requires clinician-guided medication context.
Legal and regulatory status
As checked on 2026-08-02, FDA does not approve dietary supplements for safety and effectiveness before they are marketed. This is United States regulatory context and does not establish vitamin K safety, effectiveness, or regulatory status in other jurisdictions.
Practical buying and quality notes
- The current catalog has 25 active Vitamin K listings, mostly powders. A K1 1% bulk powder price per gram is not comparable with a K2 MK-7 capsule or powder until the label identifies the active form, concentration, and microgram serving.
- Before considering two offers as alternatives, identify whether each label names K1 or K2/MK-7, whether a powder is diluted or concentrated, and how many micrograms of vitamin K are in a serving. Inventory counts and price rails can change; the product label controls the comparison.
FAQ
Is vitamin K1 the same as vitamin K2 MK-7?
1No. K1 is phylloquinone, while K2 includes menaquinones such as MK-7. Supplements can contain different vitamin K forms, so form and labelled amount should be checked before comparing products or transferring evidence.
Does vitamin K improve focus?
4Current clinical literature does not establish vitamin K supplementation as an acute focus or attention enhancer. Essential nutrient roles and reported cognition associations do not prove a cognitive-enhancement effect.
References
- NIH Office of Dietary Supplements. Vitamin K Fact Sheet for Health Professionals.
- PubChem Compound Summary for CID 5284607, Phylloquinone.
- PubChem Compound Summary for CID 5287554, Menaquinone-7.
- Alisi L, Cao R, De Angelis C, et al. The Relationships Between Vitamin K and Cognition: A Review of Current Evidence. Front Neurol. 2019.
- U.S. Food and Drug Administration. Information for Consumers on Using Dietary Supplements.