Vitamin K is a fat-soluble vitamin that cannot be made by our bodies although bacteria in our gut can probably make about half our needs. As a result intake from food need only supply about half our requirement. The USA standard recommends adults consume 70 to 140mcq a day or about 2mcq per kg of body weight. That means that larger people can have more. Babies should have 10 to 20mcq and children and adolescents about 15 to 100mcq.
Newborn babies can sometimes suffer vitamin K deficiency, as can people who do not absorb fat. Those with liver disease may require more vitamin K. Some proteins in bone and kidney are vitamin K dependent, so that vitamin K may have functions in these tissues as well.
Vitamin K is mostly known for its involvement in the formation of coagulation factors in our blood that help reduce the risk or haemorrhaging or bleeding. This becomes important if you are susceptible to blood clotting and are on a preventive medication such as warfarin.
Warfarin interferes with the formation of the vitamin-K-dependent clotting factors. If you are taking warfarin, it is important to have a stable intake of vitamin K. It is not suggested that Vitamin K rich foods be omitted except for dark leafy greens such as spinach. Other foods should be monitored to help to maintain a steady intake of the vitamin.
Soybean, Canola and olive oil are reasonably high in Vitamin K so choosing Safflower or corn oil instead is recommended although if the quantity is small, it is of little concern.
Restrict consumption of foods high in vitamin K to ½ cup or less. This applies to wheat germ, wheat bran, spinach, soybeans, lettuce, cauliflower, cabbage, broccoli and liver.
Those foods containing moderate amounts of vitamin K such as carrots, peas, strawberries, asparagus, green beans, potatoes and mince can be consumed safely in quantities up to 1 cup.
Foods such as apples, oranges and milk containing very little Vitamin K.
There is a new anticoagulant called Exanta that is waiting approval in the USA and Europe. This does not react with Vitamin K so in the future if it becomes available here watching Vitamin K may not be such an issue.
Added to site on : Monday, 7 March 2005