Low Dose Supplementation to Improve Anticoagulation Control With Oral Vitamin K as an Adjuvant to Warfarin Therapy

Vitamin K1 tablets (100 micrograms per tablet) will be taken by patients randomized to the Vitamin K arm. Dosage is two tablets per day (200 micrograms per day) to be taken with warfarin for the 6 month study period.

Lactose-based placebo tablets (identical in appearance to the Vitamin K1 tablets) will be taken by patients randomized to the placebo arm. Dosage is two tablets per day to be taken with warfarin for the 6 month study period.