VITAMIN K

VITAMIN K

Vitamin K is naturally produced by the bacteria in the intestines, and plays an

essential role in normal blood clotting, promoting bone health, and helping to produce proteins for blood, bones, and kidneys.

 Food Sources for Vitamin K

Good food sources of vitamin K are green, leafy-vegetables such as turnip greens, 

spinach, cauliflower, cabbage and broccoli, and certain vegetables oils including 

soybean oil, cottonseed oil, canola oil and olive oil. Animal foods, in general, 

contain limited amounts of vitamin K.

 RDA Recommended Dietary Allowance (RDA) 

Males and females age 14 - 18: 75 mcg/day; Males and females age 19 and older:

90 mcg/day

 Vitamin K Deficiency

Hemorrhage can occur due to sufficient amounts of vitamin K. Vitamin K

deficiency may appear in infants or in people who take anticoagulants, such as

Coumadin (warfarin), or antibiotic drugs. Newborn babies lack the intestinal

bacteria to produce vitamin K and need a supplement for the first week. Those on 

anticoagulant drugs (blood thinners) may become vitamin K deficient, but should 

not change their vitamin K intake without consulting a physician. People taking 

antibiotics may lack vitamin K temporarily because intestinal bacteria are

sometimes killed as a result of long-term use of antibiotics. Also, people with

chronic diarrhea may have problems absorbing sufficient amounts of vitamin K

through the intestine and should consult their physician to determine if

supplementation is necessary.

 Vitamin K toxicity

Although no Tolerable Upper Intake Level (UL) has been established for vitamin

K, excessive amounts can cause the breakdown of red blood cells and liver

damage. People taking blood-thinning drugs or anticoagulants should moderate

their intake of foods with vitamin K, because excess vitamin K can alter blood

clotting times. Large doses of vitamin K are not advised.