Add your supplements, foods, meals — and any medications you take — to see how they interact. Findings are grouped by severity: what to avoid, what needs care or timing, and what actually works better together.
Vitamin K directly counteracts warfarin — it can restore clotting and raise clot risk.
Why: Vitamin K is the antidote to warfarin; it regenerates the clotting factors warfarin suppresses.
→ Do not start/stop vitamin K without your prescriber; keep intake consistent and monitor INR.
Vitamin K2 counteracts warfarin and can reduce its anticoagulant effect.
Why: Vitamin K regenerates clotting factors warfarin suppresses.
→ Only under prescriber guidance with INR monitoring.
Reduces anticoagulant effect
Why: Same as warfarin - vitamin K antagonism
Reduces anticoagulant effect
Why: Vitamin K antagonist anticoagulant
High-dose vitamin E can increase bleeding risk with blood thinners.
Why: Mild antiplatelet effect at high doses.
→ Avoid high doses without prescriber guidance.
Potassium supplements with these drugs can cause dangerously high potassium.
Why: These drugs reduce potassium excretion.
→ Only supplement potassium under prescriber guidance with labs.
Antibiotics kill gut bacteria that produce vitamin K2; may need more K
Why: Reduced intestinal vitamin K synthesis
Can cause vitamin K deficiency; bleeding risk
Why: Interfere with vitamin K recycling
Reduces vitamin K absorption
Why: Binds fat-soluble vitamins in gut
Reduces vitamin K absorption
Why: Blocks fat absorption including fat-soluble vitamins
High vitamin E may interfere with vitamin K function
Why: Competitive inhibition of vitamin K-dependent clotting
Reduces vitamin K absorption
Why: Fat-soluble vitamin binding
Vitamin D: Glucocorticoids (reduced vitamin D effectiveness)
Vitamin D: Anticonvulsants like phenytoin (increased vitamin D metabolism)
Vitamin D: Orlistat (reduced fat-soluble vitamin absorption)
Vitamin K: Warfarin - must keep intake consistent
Vitamin B1 (Thiamine): Loop diuretics deplete
Vitamin B2 (Riboflavin): None significant
Niacin (Vitamin B3): Statins (myopathy risk)
Niacin (Vitamin B3): Blood pressure meds
Vitamin B12 (Cobalamin): Metformin reduces absorption
Vitamin B12 (Cobalamin): PPIs reduce absorption
Selenium: May affect thyroid medication needs
Copper: Penicillamine, zinc, antacids reduce absorption
Chromium Picolinate: May enhance diabetes meds
Vitamin K2: Warfarin and other coumarin anticoagulants—may reduce anticoagulant effect; consistency is key
Vitamin K2: Some antibiotics (broad-spectrum) may reduce K2 production by gut bacteria
Magnesium can bind these drugs and reduce their absorption.
Why: Cation chelation in the gut.
→ Separate magnesium from these medications by 2–4 hours.
Calcium can bind these drugs and reduce their absorption.
Why: Cation chelation in the gut.
→ Separate calcium from these medications by 2–4 hours.
Minimal interaction - does not depend on vitamin K
Why: Direct factor Xa inhibitor - not vitamin K dependent
Minimal interaction
Why: Direct factor Xa inhibitor
Minimal interaction
Why: Direct thrombin inhibitor
May reduce vitamin K levels
Why: Gut bacteria disruption
May reduce vitamin K absorption
Why: Less effect than older agents
May interfere with vitamin K absorption
Why: Competition for absorption
Vitamin D: Magnesium (needed for vitamin D metabolism)
Vitamin D: K2 (complementary for bone and cardiovascular health)
Vitamin B1 (Thiamine) pairs well with Magnesium.
Vitamin B2 (Riboflavin) pairs well with Magnesium.
Folate pairs well with Vitamin B12 (Cobalamin).
