Vitamin K is a fat-soluble vitamin, very common in foodstuffs; however, 80% of it is produced directly by the body. There are 2 types of Vitamin K: Vitamin K1, which is found essentially in green vegetables, and Vitamin K2, which is produced by the bacteria in our intestinal flora.
Principal natural sources of Vitamin K
Plant sources: Vitamin K1 is mainly found in green vegetables such as broccoli, cabbage, cauliflower, spinach, artichoke, lettuce, cress, asparagus, beans, parsley, leek and peas.
Animal sources: In small quantities in meat, liver, eggs, dairy products, some fruits (tomatoes, grapefruit, bananas, oranges etc.), certain cereals (lucerne, oats, maize), leguminous vegetables and potatoes.
Other sources: Vitamin K2 is produced mostly by bacteria in the colon, but is also present in foods produced through fermentation: fermented miso or soya, cheese, yoghurt, fish oils and nuoc-mam sauce.
Properties of Vitamin K
Vitamin K, or menaquinone, assists with normal blood coagulation and helps maintain healthy bones.
Recommended Daily Intake
The recommended intake is not well known, as the body synthesises the vitamin. Recommendations suggest a dietary intake of 75 mcg daily. Studies of bone mineralisation show that an additional daily intake of 45 mcg can be beneficial.
The need is more significant in the following people:
- Newborn (especially premature) babies.
- Babies fed using mother's milk.
- Pregnant or nursing women.
- Elderly people from 60 years onwards.