Vitamin K1

Specialist

also phylloquinone

What it isVitamin K1 is the plant-derived form of vitamin K, abundant in leafy greens. The liver uses it primarily to activate clotting factors.

DoesDrives the activation of clotting factors II, VII, IX, and X.

GoodAdequate K1 supports normal clotting and is easily obtained through diet.

BadDeficiency causes bleeding tendencies. Rare in adults eating any greens; relevant for newborns.

Standard
0.1–2.2 ng/mL.
Optimal
0.8–2.0 ng/mL (higher is good within range)
Modifiers
Falls with fat malabsorption, antibiotics, warfarin use.

How to optimize

Lifestyle
Diet
Kale, spinach, broccoli, brussels sprouts, parsley.
Supplements
Generally not needed if eating greens.
Peptides
Drugs
Warfarin antagonizes vitamin K; phytonadione (K1) reverses warfarin.