Vitamin K

Summary

Vitamins are substances that your body needs to grow and develop normally. Vitamin K helps your body by making proteins for healthy bones and tissues. It also makes proteins for blood clotting. If you don't have enough vitamin K, you may bleed too much.

Newborns have very little vitamin K. They usually get a shot of vitamin K soon after they are born.

If you take blood thinners, you need to be careful about how much vitamin K you get. You also need to be careful about taking vitamin E supplements. Vitamin E can interfere with how vitamin K works in your body. Ask your health care provider for recommendations about these vitamins.

There are different types of vitamin K. Most people get vitamin K from plants such as green vegetables, and dark berries. Bacteria in your intestines also produce small amounts of another type of vitamin K.

Learn More

• Facts about Vitamin K (University of Florida, Institute of Food and Agricultural Sciences)
• Find a Registered Dietitian Nutritionist (Academy of Nutrition and Dietetics)
• Hemorrhagic disease of the newborn (Medical Encyclopedia) Also in Spanish
• Important Information to Know When You Are Taking: Warfarin (Coumadin) and Vitamin K (National Institutes of Health, Clinical Center) - PDF Also in Spanish
• Protect Your Baby from Bleeds: Talk to Your Healthcare Provider about Vitamin K (Centers for Disease Control and Prevention) - PDF Also in Spanish
• Vitamin K (Harvard School of Public Health)
• What Is Combined Deficiency of Vitamin K-Dependent Clotting Factors? (World Federation of Hemophilia) Also in Spanish

Clinical Trials

• ClinicalTrials.gov: Vitamin K (National Institutes of Health)

Journal Articles References and abstracts from MEDLINE/PubMed (National Library of Medicine)

• Article: Antithrombotic Therapy after Acute Coronary Syndrome or PCI in Atrial Fibrillation.
• Article: Educating Parents About Vitamin K in the Newborn Using Knowles' Theory...
• Article: Direct-Acting Oral Anticoagulants and Warfarin-Associated Intracerebral Hemorrhage Protocol Reduces Timing of...
• Vitamin K -- see more articles

Patient Handouts

• Vitamin K (Medical Encyclopedia) Also in Spanish