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Vitamin K1
Specialistalso 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.
Reference ranges are general adult lab norms; optimal ranges are editorial picks from the longevity literature — not medical advice. Always interpret results with your physician.
within Vitamins