Vitamin K
A fat-soluble vitamin the body needs to make proteins for blood clotting and for bone and tissue health.
What it is
Vitamin K is a fat-soluble vitamin your body stores in the liver and other tissues, including the brain, heart, pancreas, and bone. It is used to make proteins involved in blood clotting and in maintaining healthy bones and tissues. Most people get enough vitamin K from food, particularly green leafy vegetables and other vegetables; the body can also produce some vitamin K itself.
Food and timing considerations
Vitamin K is fat-soluble and found in foods such as green leafy vegetables and other vegetables. People taking a vitamin K-antagonist blood thinner such as warfarin are specifically advised to keep their day-to-day vitamin K intake consistent rather than avoiding it, since large swings in intake (not vitamin K itself) are what affect how the medication works.
Known interaction categories
- Insufficient evidence
- Use caution
Published interaction pages on this site
- Vitamin K and LisinoprilInsufficient evidence
- Vitamin K and WarfarinUse caution
- Vitamin K and Vitamin DInsufficient evidence
- Vitamin K and CalciumInsufficient evidence
- Vitamin K and IronInsufficient evidence
- Vitamin K and CiprofloxacinInsufficient evidence
- Vitamin K and CreatineInsufficient evidence
- Vitamin K and SpironolactoneInsufficient evidence
- Vitamin K and St. John's WortInsufficient evidence
- Vitamin K and CaffeineInsufficient evidence
- Vitamin K and CopperInsufficient evidence
- Vitamin K and LevothyroxineInsufficient evidence
- Vitamin K and Vitamin B12Insufficient evidence
- Vitamin K and PotassiumInsufficient evidence
- Vitamin K and TurmericInsufficient evidence
- Vitamin K and ZincInsufficient evidence
- Vitamin K and DoxycyclineInsufficient evidence
- Vitamin K and OmeprazoleInsufficient evidence
- Vitamin K and CoQ10 (Coenzyme Q10)Insufficient evidence
- Vitamin K and MagnesiumInsufficient evidence
- Vitamin K and ProbioticsInsufficient evidence
- Vitamin K and SertralineInsufficient evidence
- Vitamin K and MetforminInsufficient evidence
- Vitamin K and MelatoninInsufficient evidence
- Vitamin K and AtorvastatinInsufficient evidence
Sources
Last reviewed 2026-08-22
Medical information disclaimer: this information is general and educational. It does not diagnose conditions, prescribe treatment, or determine whether a combination is safe for you personally. Follow your prescription label and ask a pharmacist or clinician before starting, stopping, or combining products. Full disclaimer.