Vitamin K & Warfarin side effects.

Vitamin K and Warfarin interaction

Vitamin K and Warfarin may fight each other. If you’re in the medication of Warfarin, better inform your physician for your eating habits. Sometimes vitamin K is too much.

What is Warfarin used for?

Warfarin, sold under the brand name Coumadin among others, is an anticoagulant, meaning it’s a blood thinner drug. Warfarin reduces the formation of blood clots. 

Warfarin can prevent blood clots in veins and arteries. Also, it may reduce the risk of stroke and heart attack.

Vitamin K & Warfarin side effects.

Vitamin K helps your blood clot. Otherwise, we would bleed excessively. Moreover, the wounds wouldn’t be healed as easily.

Vitamin K is very important for the proper function of the liver. The liver needs vitamin K to make some clotting factors. Blood clotting factors help to make blood clot. 

On the other hand, Warfarin makes your blood clot more slowly. In a sense, vitamin K and Warfarin fight each other.

Too much vitamin K isn’t good for you.

Although there isn’t an upper safe dose of vitamin K for healthy people, people who take blood thinners should keep their vitamin K intake constant.

Vitamin K and Warfarin compete with each other. Vitamin K helps to clot the blood, while Warfarin acts as a human blood-thinner.

For this reason, it’s important to consult your physician before taking a supplement or changing your diet.


  1. Nutrients and bioactives in green leafy vegetables and cognitive decline – Prospective study
  2. Potential of commonly consumed green leafy vegetables for their antioxidant capacity and its linkage with the micronutrient profile.
  3. NCBI: The effect of fruit and vegetable intake on risk for coronary heart disease.
  4. Healthy lifestyle and preventable death: findings from the Japan Collaborative Cohort (JACC) Study.