What vitamin K does
Vitamin K is needed to make the proteins that clot blood, and helps build and maintain bones.
How much
Adults need about 70–120 µg a day.
Plant sources
Leafy greens are extraordinarily rich: kale, spinach, chard, collards, parsley and lettuce, plus broccoli, Brussels sprouts, cabbage and fermented soy (natto).
How many portions of each food would cover a day's vitamin K?
A note
If you take warfarin or similar blood thinners, you don’t need to avoid greens — keep your intake consistent from day to day and talk to your doctor before changing it.