Good sources of vitamin K
Vitamin K is found in:
- green leafy vegetables – such as broccoli and spinach
- vegetable oils
- cereal grains
Small amounts can also be found in meat and dairy foods.
How much vitamin K do I need?
Adults need approximately 1 microgram a day of vitamin K for each kilogram of their body weight.
For example, someone who weighs 65kg would need 65 micrograms a day of vitamin K, while a person who weighs 75kg would need 75 micrograms a day.
A microgram is 1,000 times smaller than a milligram (mg). The word microgram is sometimes written with the Greek symbol μ followed by the letter g (μg).
You should be able to get all the vitamin K you need by eating a varied and balanced diet.
Any vitamin K your body doesn't need immediately is stored in the liver for future use, so you don't need it in your diet every day.
What happens if I take too much vitamin K?
There's not enough evidence to know what the effects might be of taking high doses of vitamin K supplements each day.