Information
Top 10 Variables: Dietary Vitamin K
Sunday, July 1, 2007
PTINR.com Staff
Diet remains the most common topic questioned by patients taking Coumadin - how responsible is diet for fluctuating INR?
Vitamin K can reverse the effects of warfarin. Vitamin K is a relatively unknown vitamin not listed on food or beverage labels. In addition to playing an important role in helping the human body to form clots for healing purposes – vitamin K helps in health bone development and maintenance. Vitamin K, even for warfarin (Coumadin ®) patients, is not the enemy.
Patient counseling always includes a discussion about vitamin K for patients taking Coumadin® (warfarin). Counseling recommendations range from eliminating vitamin K completely from the patient’s diet to keeping an ordinary intake of vitamin K - provided it is kept consistent.
Recent studies have shown that patients experiencing severe fluctuations in INR test results may actually benefit from dietary vitamin K supplement treatment. In controlled trials, increasing the vitamin K in some patients with fluctuating INR test results found more consistent, in range test results. Patients should not experiment with vitamin K intake without consulting their physician. Stabilizing INR test results using vitamin K as a tool is a healthcare-patient team effort.
A high intake of vitamin K over time will decrease INR test results and lower patients’ defense against stroke. Patients who experience an unexpected low test result should review the previous 5 days meals and beverage in take. It is very difficult for a patient to recall all previous 15 meals of course. QAS offers the weekly Vitamin K Diary to help patients review their previous week’s meals and vitamin K intake.
The vitamin K diary is an excellent tool to evaluate various new foods and their potential affect on INR test results. Use the diary along with the Vitamin K Registry to help determine portion sizes and make the diary easier to use.
Most patients know vitamin K is found in dark, leafy green vegetables but hidden sources include salad dressings and some oils. Patient with questions about a food should consult the vitamin K registry. If the product is not listed - a call to a local hospital may have a dietitian that can offer support.
Keeping an INR test result within range requires a consistent intake of vitamin K, good communication and weekly testing to evaluate the impact of diet and beverages. A lower than expected test result may be a result of higher than normal vitamin K intake 3-5 days prior to the actual blood test.