Vitamin K and Warfarin: Can You Take Them Together?

Here's what FDA drug labeling and NIH supplement data show.

SEVERE

Interaction Found

What happens: Vitamin K directly counteracts warfarin's mechanism of action (inhibiting vitamin K-dependent clotting factors).

What to do: Maintain consistent vitamin K intake. Do not start or stop supplements without consulting your doctor.

Source: FDA-approved drug labeling and NIH Office of Dietary Supplements fact sheets.

Learn more

Warfarin — full safety profile, side effects, and all known interactions.

Vitamin K — supplement labels containing this ingredient.

Frequently asked questions

Can I take Vitamin K with Warfarin?

Maintain consistent vitamin K intake. Do not start or stop supplements without consulting your doctor.

What happens if you take Vitamin K and Warfarin together?

Vitamin K directly counteracts warfarin's mechanism of action (inhibiting vitamin K-dependent clotting factors).

What should I do if I take both?

Maintain consistent vitamin K intake. Do not start or stop supplements without consulting your doctor. Always consult your healthcare provider before combining supplements and medications.

SafeCheck provides drug interaction information from FDA-approved product labeling (openFDA). This is for informational purposes only and is not medical advice. Always consult your healthcare provider before making medication decisions.