vitamin k
18 interactions related to vitamin k
parsley + warfarin
Fresh parsley is extraordinarily dense in vitamin K1 - about 1,640 mcg per 100 grams, or roughly 62 mcg per tablespoon - so although typical garnish-sized servings are small, large culinary uses (tabbouleh, chimichurri, parsley smoothies, juicing) can deliver enough vitamin K to oppose warfarin and lower the INR.
matcha + warfarin
Matcha is powdered whole green tea leaf, so each serving delivers far more vitamin K than a normal brewed cup. Vitamin K is the cofactor warfarin antagonises, so large or fluctuating matcha intake can lower INR and reduce the anticoagulant effect, similar to the documented green tea-warfarin case report.
fat-soluble vitamins + dietary fat
Vitamins A, D, E, and K depend on bile acid micelle formation in the small intestine for absorption, and that process requires dietary fat as a trigger for bile secretion. Taking these vitamins without fat reduces absorption efficiency substantially, with studies on vitamin D showing roughly 30-50% greater absorption when taken with a meal containing fat.
noni juice + warfarin
Noni juice (Morinda citrifolia) products vary substantially in vitamin K content - one published case of warfarin resistance was attributed to a high-vitamin K noni preparation. Noni has also been linked to drug-induced liver injury and may induce CYP2C9, both of which can destabilize warfarin in unpredictable directions.
green tea + warfarin
Green tea leaves contain vitamin K, which is a cofactor for hepatic synthesis of the clotting factors that warfarin inhibits. Large or fluctuating intake of green tea can lower INR and reduce the anticoagulant effect of warfarin, as documented in a published case report.
collard greens + warfarin
Collard greens are one of the highest-vitamin-K vegetables available, with roughly 836 mcg of vitamin K1 per cup cooked - more than seven times the daily adequate intake for adults. Sudden increases or decreases in consumption directly antagonize warfarin and can push the INR out of its therapeutic range.
spinach + warfarin
Spinach is one of the highest dietary sources of vitamin K1 (phylloquinone), with roughly 145 mcg per cup raw and 889 mcg per cup cooked. Because warfarin works by blocking vitamin K-dependent clotting factor synthesis, large or fluctuating spinach intake antagonizes warfarin and can drop the INR into a sub-therapeutic range, raising clot risk.
turnip greens + warfarin
Turnip greens contain about 529 mcg of vitamin K1 per cup cooked - roughly five times the daily adequate intake. Because warfarin works by blocking vitamin K-dependent clotting factor synthesis, large or fluctuating servings can drop the INR into a sub-therapeutic range and raise clot risk.
romaine + warfarin
Romaine lettuce contains roughly 48 to 60 mcg of vitamin K1 per cup shredded - lower than dark cooking greens but still meaningful at multi-cup salad servings. Large daily salads or romaine-heavy juices can supply enough phylloquinone to oppose warfarin and drift the INR downward.
microgreens + warfarin
Microgreens - the immature seedlings of vegetables and herbs harvested 7 to 21 days after germination - concentrate nutrients on a per-gram basis. Phylloquinone content varies widely by species, from roughly 0.6 to 4.1 mcg per gram, with brassica and amaranth microgreens highest. Daily handfuls or smoothie additions can supply enough vitamin K to oppose warfarin and shift the INR.
broccoli + warfarin
Broccoli is rich in vitamin K1 (phylloquinone), the very cofactor warfarin blocks to suppress clotting factor synthesis. Large or wildly inconsistent intake can lower the INR and reduce warfarin's anticoagulant effect, raising clot risk.
sauerkraut + warfarin
Sauerkraut is fermented green cabbage and contains roughly 18 to 70 micrograms of vitamin K1 per cup, depending on whether the brine is consumed and how the cabbage was prepared. Vitamin K1 supplies the cofactor for the very clotting factors warfarin blocks, so changing sauerkraut intake can shift INR and weaken anticoagulation control.
brazil nuts + warfarin
Brazil nuts contain no detectable vitamin K (phylloquinone) per USDA analysis, so they do not antagonize warfarin's mechanism. Their main concern is the very high selenium content, which has no established direct interaction with warfarin metabolism.
walnuts + warfarin
Walnuts contain only trace amounts of vitamin K (about 2.7 mcg per 100 g) and small quantities of plant-based omega-3 (alpha-linolenic acid). Typical servings are unlikely to meaningfully shift INR, but dramatic changes in intake or very large daily portions could theoretically nudge anticoagulation in either direction.
swiss chard + warfarin
Swiss chard delivers approximately 299 mcg of vitamin K1 per cup raw and over 570 mcg per cup cooked - several times the adult adequate intake. As a direct vitamin K antagonist, warfarin's effect is reduced when dietary phylloquinone rises, so sudden increases in swiss chard intake can lower the INR into a sub-therapeutic, clot-prone range.
pumpkin seeds + warfarin
Pumpkin seeds (pepitas) contain a moderate amount of vitamin K, with about 54 mcg per half-cup of dried roasted seeds. Large or fluctuating intakes can shift INR through the standard vitamin K mechanism, while typical snack portions are unlikely to cause problems.
mustard greens + warfarin
Mustard greens are a dark leafy green packed with vitamin K1, providing roughly 419 mcg per cup cooked - several times the adult daily adequate intake. Because warfarin works by blocking vitamin K-dependent clotting factor synthesis, large or fluctuating intake can lower the INR and reduce clot protection.
kimchi + warfarin
Kimchi is fermented Napa cabbage and contains roughly 65 micrograms of vitamin K1 per cup, which provides the cofactor for the very clotting factors warfarin blocks. Inconsistent kimchi intake can lower the INR and reduce warfarin's anticoagulant effect, increasing clot risk.