Vitamin k foods & blood thinners

Updated July 19, 2017

Vitamin K and certain blood-thinning medications are a potentially dangerous combination. If you are taking one of these medications, it is important to know what foods are rich in vitamin K and how much should be included in your daily diet.

Vitamin K

Vitamin K is found in some foods and in supplements. It is also produced in your body's gastrointestinal tract. Vitamin K plays a pivotal role in maintaining healthy blood chemistry, especially in maintaining proper clotting function. A deficiency in vitamin K can lead to potentially dangerous conditions such has internal bleeding.

Vitamin K and Blood Thinners

If you have a history of stroke, heart attack or excessive and dangerous blood clotting, such as deep vein thrombosis, your doctor may prescribe a blood thinner to help protect you from further incidents. Warfarin, also marketed as Coumadin and Jantoven, is one of the most commonly prescribed medications for these conditions, and vitamin K can interfere with and even counter the intended benefits of this drug.

Vitamin K and Diet

Vitamin K is found predominately in dark green, leafy vegetables like kale, Brussels sprouts, Swiss chard, collard greens and parsley. It is also present in cereals, soya beans and certain soy products. If your doctor prescribes a drug like warfarin, ask her for specific dietary guidelines so you can keep your daily consumption of vitamin K within safe limits.


Just because you are taking a blood thinner, don't eliminate foods containing vitamin K from your diet. Vitamin K is an important factor in keeping bones strong and healthy. Ask your doctor how much vitamin K is allowed in your daily diet, then make sure you stay within these parameters. Wide fluctuations in the amount of vitamin K ingested on a day-to-day basis could cause complications, so be consistent.


Blood thinners like wayfarin can interact negatively with other pharmaceuticals and homeopathic remedies, and vitamin K may be present in vitamins and supplements. Always inform your doctor of any non-prescription or prescription medications, herbal supplements and vitamins you may be taking.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author