Overview
Leafy-green K1 essential for hepatic coagulation factors.
- Whole-food sources (animal products for fat-soluble and B-complex vitamins; produce for water-soluble vitamins)
- Fortified foods (cereals, dairy, plant milks, nutritional yeast)
- Multivitamins or stand-alone supplements in synthetic or food-derived form
- Capsule or softgel
- Sublingual tablet or liquid
- Methylated active form for sensitive individuals
- Multivitamin matrix
Mechanism of action
Cofactor for γ-glutamyl carboxylase activating clotting factors II, VII, IX, X.
- · Cofactor for γ-glutamyl carboxylase activating clotting factors II, VII, IX, X
Effects on the body
Organ system effects
Vitamin K1 (Phylloquinone) supports endothelial function, lipid profile, or blood-pressure regulation in cardiovascular trials.
Vitamin K1 (Phylloquinone) contributes to bone mineralization, osteoblast activity, or calcium-phosphate homeostasis.
Evidence-based benefits
Required for normal coagulation
Strong evidencePotential side effects
- · Antagonizes warfarin
Drug interactions
Supplement interactions
- Omega-3Anti-inflammatory cardiovascular synergy.
- CoQ10Supports mitochondrial energetics in cardiac tissue.
No specific avoidances listed.
Dosing & bioavailability
Where to buy
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Third-party testedIndependently verified Vitamin K1 (Phylloquinone) — look for USP, NSF, or Informed Sport seals on the label for purity and dose accuracy.Vitamin K1 (Phylloquinone) third party tested NSF
CapsulesPre-measured Vitamin K1 (Phylloquinone) capsules — easiest for travel and consistent daily dosing without scoops or scales.Vitamin K1 (Phylloquinone) capsules
PowderBulk unflavored Vitamin K1 (Phylloquinone) powder — best cost-per-gram and flexible dosing for stacking or mixing into drinks.Vitamin K1 (Phylloquinone) powder unflavored
Best sellersMost-purchased Vitamin K1 (Phylloquinone) products on Amazon — a quick way to see what's reviewed widely before you commit.Vitamin K1 (Phylloquinone) best sellerScientific evidence8Show studiesHide studies
Phylloquinone and bone in women
Booth SL, et al.
3-year DB-RCT in 452 older adults.
No effect on BMD but reduced fracture markers.
PubMed: Vitamin K1 (Phylloquinone) — Required for normal coagulation
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