Celery is one of a few negative-calorie foods, it takes more calories to chew and digest than it provides the body for energy. While this is an ideal food for dieters, it is a precautionary food for people on warfarin. Celery, celery seed and celery oil is generally regarded as safe (GRAS) by the FDA when taken in herbal form.
The product is available in capsule form, tea leaves and of course the natural form of fresh celery. Celery contains 12 micrograms of vitamin K per half a cup (3.5 ounces). In addition to calcium, magnesium, and iron, celery contains natural elements including volatile oils, flavonoids, coumarins, and linoleic acid. The coumarins are the enzymes of concern for people taking warfarin.
If coumarin sounds familiar, it should; Coumadin® is one of the brand name drugs for warfarin. Warfarin is a name derived from the acronym Wisconsin Alumni Research Foundation and the ARIN comes from the suffix of the enzyme coumarin.
Celery's coumarin enzymes and vitamin K amount make it a concern for people taking warfarin as it could affect your INR levels. As always, discuss this food with your doctor before regularly consuming celery or celery by-products.