Activates clotting factors and proteins involved in bone metabolism.
Switzerland age 18–65: 70 µg/day.
K1: leafy greens, broccoli and vegetable oils. K2: fermented foods and some animal foods.
Bleeding tendency and prolonged clotting; rare in adults and usually related to malabsorption or medicines.
Vitamin K is established for coagulation. Added benefit of K2 supplements for hard bone or vascular outcomes is not settled.
Easy bruising is nonspecific; spontaneous or heavy bleeding is a medical warning sign.
Fat malabsorption, prolonged antibiotics, liver disease and vitamin-K-antagonist anticoagulants.
Assess coagulation and cause clinically; do not self-diagnose from skin signs.
With warfarin/phenprocoumon keep intake consistent and discuss changes; do not self-supplement.
No usual UL is established for natural forms; medication interactions remain crucial.