Vitamin K1 (Phylloquinone)

The essential vitamin for blood clotting and bone health.

Also known as: Phylloquinone • Phytonadione

other Names
Phylloquinone, Phytonadione
primary Benefits
Blood clotting, bone health, cardiovascular support
common Dose
90-120 mcg per day
best Form
Phylloquinone from food sources or supplements
timing
With a meal containing fat to enhance absorption
safety Rating
Generally safe, but high doses can interfere with blood thinners

Overview

Vitamin K1, also known as phylloquinone, is a fat-soluble vitamin primarily found in leafy green vegetables. It plays a crucial role in blood coagulation by activating proteins required for blood clotting. It also participates in bone metabolism and helps maintain bone density.

Key Benefits

Essential for Blood Clotting

Vitamin K1 is necessary for the synthesis of several proteins involved in the blood clotting cascade, preventing excessive bleeding.

Supports Bone Health

It helps activate osteocalcin, a protein that binds calcium to the bone matrix, contributing to bone strength and density.

May Promote Heart Health

By helping to prevent the calcification of arteries, Vitamin K1 may play a role in maintaining cardiovascular health.

Dosage & How to Take

The recommended daily intake for adults is 90 mcg for women and 120 mcg for men. Higher doses may be used for specific medical conditions under a doctor's supervision.

PurposeDoseNotes
General Health90-120 mcg per dayAdequate intake for most adults.
To counteract warfarin1-10 mg per dayUsed under medical supervision to manage anticoagulant effects.

Best Time to Take

Best taken with a meal that includes some fat to maximize absorption.

With or Without Food

Should be taken with food, especially fats.

Forms & Bioavailability

FormAbsorptionBest ForNotes
Phylloquinone (K1)MediumGeneral supplementation and dietary intake.Found in leafy greens and supplements.
Menaquinone (K2)HighBone and cardiovascular health.Found in fermented foods and animal products.

Side Effects & Safety

Common

  • Generally well-tolerated

Rare

  • Allergic reactions to supplements

Contraindications

  • Individuals taking anticoagulant medications (blood thinners) like warfarin should consult their doctor before taking Vitamin K supplements.

Interactions

Warfarin (Coumadin)Important

Vitamin K can decrease the effectiveness of warfarin, increasing the risk of clotting.

Orlistat (Xenical, Alli)Moderate

Can reduce the absorption of fat-soluble vitamins, including Vitamin K.

Scientific Research

2017Journal of Osteoporosis

Vitamin K and bone health: a review of the evidence

Evidence suggests that Vitamin K plays an important role in maintaining bone health and reducing the risk of fractures.

2015Journal of Nutrition and Metabolism

The role of vitamin K in cardiovascular health: a review of the literature

Vitamin K may help to prevent vascular calcification, a risk factor for cardiovascular disease.

Food Sources

Kale
Spinach
Collard greens
Broccoli
Brussels sprouts
Lettuce

Products With Vitamin K1 (Phylloquinone)

5 products in our database contain this ingredient

Frequently Asked Questions

Medical Disclaimer

This content is for educational and informational purposes only and is not intended as medical advice. Always consult with a qualified healthcare professional before starting any supplement regimen, especially if you have pre-existing health conditions or are taking medications. The statements on this page have not been evaluated by the Food and Drug Administration.