Vitamin K

Vitamin K is also known as phylloquinone.

What does Vitamin K do?

Vitamin K is needed for proper bone formation and blood clotting, in both cases by helping the body transport calcium. Vitamin K is used by medical doctors when treating an overdose of the drug warfarin. Also, medical doctors prescribe vitamin K to prevent excessive bleeding in people taking warfarin who require surgery.

Where is Vitamin K found?

Leafy green vegetables are the best source of vitamin K.

Who is likely to be deficient?

A vitamin K deficiency, which causes uncontrolled bleeding, is rare, except in individuals with certain malabsorption diseases. All newborn infants receive vitamin K to prevent deficiencies that sometimes develop in breast-fed infants.

How much is usually taken?

Many physicians suggest 65–80 mg per day, a level that can be achieved without supplements by eating vegetables.