How Much Vitamin K Should You Take In One Day?

Vitamin K is a fat-soluble vitamin essential for proper blood clot formation, cell growth and bone development. People who don't get enough of this nutrient are at risk of developing poor blood clotting, which may cause easy bruising, bleeding gums, nosebleeds or, in severe cases, bleeding within the skull. The amount of vitamin K you should take in one day primarily depends upon your age or gender. Consult your medical care provider if you have questions about how much vitamin K you should get on a daily basis.

For Healthy Adults

For healthy adults, the daily recommended intake of vitamin K is higher for men than women. Men need 120 mcg of vitamin K, while women only need 90 mcg of this vital nutrient, according to the Linus Pauling Institute at Oregon State University. Women age 19 or older who are pregnant or breast-feeding should also get 90 mcg of vitamin K daily. Maintaining a diet full of vitamin K-rich foods, including green leafy vegetables, can help you reach your daily intake requirements for vitamin K. However, if you find it difficult to get enough vitamin K in your diet, vitamin K supplements may be incorporated into your regimen.

For Adolescents and Preteens

Daily vitamin K intake recommendations for teens and preteens ages 9 to 13 are 75 mcg and 60 mcg, respectively. Do not administer vitamin K supplements to children under age 18 unless your pediatrician recommends otherwise.

For Children and Toddlers

Children ages 4 to 8 need to get 55 mcg of vitamin K every day. The daily vitamin K requirement for toddlers up to 3 years of age is only 30 mcg.

For Infants

Infants up to 7 months of age require 2 mcg of vitamin K each day. When infants reach 7 to 12 months old, their daily intake of vitamin K should increase to 2.5 mcg. Unfortunately, breast milk does not provide developing infants with enough vitamin K. Instead, health professionals with the American Academy of Pediatrics recommend infants receive a single injection of vitamin K at birth. If your infant's blood levels of vitamin K remain low after receiving this injection, additional vitamin K supplementation may be required.

Vitamin K Toxicity

There are three supplemental forms of vitamin K: vitamin K-1, also called phylloquinone, vitamin K-2, also called menaquinone and vitamin K-3, also called menadione. The most common over-the-counter vitamin K supplement is vitamin K-1. Treatment with vitamins K-1 or K-2 in excess of the recommended daily guidelines is not toxic; however, taking too much vitamin K-3 may cause cell damage. Vitamin K-3 toxicity may cause jaundice, liver toxicity and anemia, particularly in babies. For this reason, vitamin K-3 is no longer used to reverse symptoms caused by vitamin K deficiency.