Vitamin K is a group of chemicals of which Vitamin K1 is generally obtained from ‘green’ vegetables and fruits, and Vitamin K2 which is largely consumed from meats, cheeses and eggs. Vitamin K is also produced in the human body through the actions of bacteria. Low levels of Vitamin K can increase the risk of unnecessary bleeding but such deficiencies are rare in adults except in circumstances of Crohn’s disease, celiac disease, malnourishment and alcoholism. It is standard, particularly in the Western world, to give newborn babies a single injection of Vitamin K to aid blood clotting.
The Recommended Daily Allowance (RDA) for healthy adults is between 90 mcg and 120 mcg and most people get enough Vitamin K from their diets. The use of Vitamin K supplements is rare and both the manufacturers and medical websites state that people using warfarin ‘may need to watch their diets closely to control the amount of Vitamin K they take in’.