Vitamin K


The Forgotten Vitamin


Vitamin K is one of the vitamins many people forget about. We frequently hear about the other vitamins like Vitamin C and D and their importance.

But what does Vitamin K do for you? The most important thing Vitamin K does is to clot blood.

A Vitamin K deficiency may show up with several symptoms; the most obvious being excessive bleeding. In addition to clotting, it is also instrumental in insuring calcium is directed to bones, rather than arterial walls.

Risk Factors


An adult deficiency of Vitamin K is not that common due to the wide variety of sources of Vitamin K in foods and synthesis of the vitamin in our colon.

However, a deficiency may result from these risk factors as reported in this PatientPlus article:

  • Excessive anticoagulation (blood thinning) with warfarin.
  • Liver disease: cirrhosis & malignancy decrease the synthesis of vitamin K-dependent factors.
  • Malabsorption as in celiac disease, Crohn's disease, ulcerative colitis, short bowel syndrome due to multiple abdominal surgeries, bacterial overgrowth, and chronic pancreatitis.
  • Biliary disease which affects fat absorption (including absorbing fat soluble vitamins like Vitamin K)
  • Dietary deficiency occurs in people with malnutrition, including people with alcoholism, as well as patients undergoing long-term parenteral nutrition without vitamin K supplements.
  • Drugs: colestyramine, salicylates, rifampin, isoniazid and barbiturates are some of the common drugs that are associated with Vitamin K deficiency.
  • Diseases with internally produced coagulation inhibitors (eg lupus anticoagulant and antithrombins) and paraproteinaemias such as myeloma, may cause vitamin K deficiency.
  • Miscellaneous causes include massive transfusion, disseminated intravascular coagulation, polycythaemia vera, nephrotic syndrome, cystic fibrosis, and leukemia.
  • If you need to supplement with Vitamin K due to these risk factors, it is important to know that the supplement should be taken with a meal containing fats for absorption. It is also important to look for Vitamin K2 rather than the synthetic version K3. Vitamin K2 goes right to where it is needed - blood, bones, and tissue

If you are taking prescription anticoagulants, do not supplement with Vitamin K without speaking to your healthcare practitioner. If you increase your food sources of Vitamin K, also advise your healthcare practitioner as the dosage of prescription anticoagulants may need to be adjusted. Also be aware that antacids may reduce the absorption of Vitamin K.

Quick Facts

  • The most important thing Vitamin K does is to clot blood
  • Vitamin K is essential to building strong bones and avoiding preventing heart disease
  • Vitamin K may have antioxidant and anti-inflammatory properties
  • It also plays a role in brain function
  • Topical vitamin K may help to reduce bruising
  • Vitamin K is a vitamin found in leafy green vegetables, broccoli, and Brussels sprouts
  • Fermented foods, such as natto, have the highest concentration of Vitamin K
  • Vitamin K is actually an umbrella term for a group of chemically related fat-soluble compounds -- K1, 2 & 3 -- called naphthoquinones
  • Vitamin K deficiency symptoms include easy bruising, gastrointestinal bleeding, excessive menstrual bleeding and blood in the urine
  • A vitamin K1 injection may be given to newborns and young infants in an effort to prevent hemorrhagic disease