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Vitamin K1 (phylloquinone)
Blood clotting · Bone health
Tier 2 — Promising
What it is
The primary dietary form of vitamin K, essential for proper blood clotting and bone metabolism. Deficiency is uncommon but can occur with fat malabsorption, liver disease, or long-term antibiotic use. Works alongside vitamin D for bone health. If you take warfarin, keep your vitamin K intake consistent from day to day to avoid dose fluctuations.
Efficacy
4/5
Safety
4/5
Research
3/5
Onset
3/5
Cost
5/5
Drug-int.
2/5
Dose
90–120 mcg/day (adequate intake); caution with warfarin — dose must be consistent
Time of day & tips
Take with a meal containing fat — vitamin K is fat-soluble. Keep your daily intake consistent if on warfarin. Avoid high-dose supplements without medical guidance.
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