What You Need to Know About Vitamin K

Definition: A member of the fat-soluble family of vitamins that also includes vitamin D, vitamin E and vitamin A. Vitamin K is important for normal blood clotting and may help to keep your bones strong as you age.

Vitamin K deficiency is rare, but may occur after long-term use of antibiotics. It is important to note that people who are taking blood thinners should consult with their doctors or pharmacists about vitamin K supplementation because taking extra vitamin K can reduce the effectiveness of blood thinners.

Daily Requirements

Males

1 to 3 years: 30 micrograms per day
4 to 8 years: 55 micrograms per day
9 to 13 years: 60 micrograms per day
14 to 18 years: 75 micrograms per day
19+ years: 120 micrograms per day

Females

1 to 3 years: 30 micrograms per day
4 to 8 years: 55 micrograms per day
9 to 13 years: 60 micrograms per day
14 to 18 years: 75 micrograms per day
19+ years: 90 micrograms per day

Vitamin K is found in dark green leafy vegetables, cabbage, cauliflower, broccoli, and soybeans, and it's also synthesized in your digestive tract by friendly bacteria.

More About Vitamin K

• Vitamin K is found in some different, but still natural forms. Learn more: Forms of Vitamin K
• What do people with cystic fibrosis need to know about vitamin K? Find out: Vitamin K and Cystic Fibrosis
• What foods are high in vitamin K and what are the benefits of vitamin K supplements? Here's more: What You Need to Know About Vitamin K

_Sources:

_{Vitamin K. http://www.nlm.nih.gov/medlineplus/ency/article/002407.htm.}

_{Otten JJ, Hellwig JP, Meyers LD. "Dietary Reference Intakes: The Essential Guide to Nutrient Requirements." IOM, 2006.}