1. Vitamin K
What is vitamin K?
Doctors have long used vitamin K, which promotes blood clotting, to help heal incisions in patients after surgery and to prevent bleeding problems in newborns. This vitamin also aids in building strong bones and may be useful for combating the threat of osteoporosis in older women.
Vitamin K1 is present in many foods, especially leafy green vegetables such as cabbage and spinach, and is also present in liver, cows’ milk, egg yolk and some cereals. Broccoli, spring onions and brussels sprouts are also good sources. Other foods with some vitamin K are pistachios, vegetable oils, lean meats, tomatoes and dairy products. The rest comes from bacteria that live naturally in the gut and make menaquinones (also called vitamin K2).
A synthetic form of vitamin K1 called phytomenadione (also known as phytonadione) is available for use in supplements. Menatetrenone is a type of vitamin K2, while menadione (vitamin K3) is another synthetic form used in some countries.
What does vitamin K do?
This single nutrient sets in motion the entire blood-clotting process as soon as a wound occurs. Vitamin K1 may also be important for cell-to-cell communication. Researchers have discovered that vitamin K2 also plays a protective role in bone health.
Benefits of vitamin K
Doctors may recommend preventive doses of vitamin K if post-surgery bleeding or haemorrhaging is a concern. Even when no deficiency exists, surgeons sometimes order vitamin K before an operation to reduce the risk of post-operative bleeding. (Here are 40 secrets surgeons won’t tell you.)
Consult your doctor before taking vitamin K prior to an operation, because certain types of surgery and prolonged bed rest may increase risk of unwanted blood clots.
How to take vitamin K
Supplemental vitamin K (more than is found in a multivitamin) should be taken only after consulting your doctor. When prescribed, vitamin K should be taken with meals because food enhances its absorption.
Vitamin E helps the body use vitamin K, but too much vitamin E-more than 1000 IU a day-taken long term may impair vitamin K function and increase your risk of bleeding.
High doses of vitamin E may counteract the blood coagulation properties of vitamin K, increasing the risk of bleeding.