Vitamin K deficiency is a form of avitaminosis

Avitaminosis

Avitaminosis is any disease caused by chronic or long-term vitamin deficiency or caused by a defect in metabolic conversion, such as tryptophan to niacin...

 resulting from insufficient vitamin K

Vitamin K

Vitamin K is a group of structurally similar, fat soluble vitamins that are needed for the posttranslational modification of certain proteins required for blood coagulation and in metabolic pathways in bone and other tissue. They are 2-methyl-1,4-naphthoquinone derivatives...

.

Causes

Vitamin K-deficiency may occur by disturbed intestinal uptake (such as would occur in a bile duct

Bile duct

A bile duct is any of a number of long tube-like structures that carry bile.Bile, required for the digestion of food, is excreted by the liver into passages that carry bile toward the hepatic duct, which joins with the cystic duct to form the common bile duct, which opens into the intestine.The...

 obstruction), by therapeutic or accidental intake of vitamin K-antagonists or, very rarely, by nutritional vitamin K deficiency. As a result, Gla-residues are inadequately formed and the Gla-proteins are insufficiently active.

Symptoms

Symptoms include ecchymosis

Ecchymosis

An ecchymosis is the medical term for a subcutaneous purpura larger than 1 centimeter or a hematoma, commonly called a bruise. It can be located in the skin or in a mucous membrane.-Presentation:...

, petechiae, hematoma

Hematoma

A hematoma, or haematoma, is a localized collection of blood outside the blood vessels, usually in liquid form within the tissue. This distinguishes it from an ecchymosis, which is the spread of blood under the skin in a thin layer, commonly called a bruise...

s, oozing of blood at surgical or puncture sites, stomach pains; risk of massive uncontrolled bleeding; cartilage calcification; and severe malformation of developing bone or deposition of insoluble calcium salts in the walls of arteries.

In infants, it can cause some birth defects such as underdeveloped face, nose, bones, and fingers.

Vitamin supplementation

According to a study published in the October 14, 2008 edition of PLoS Medicine, Vitamin K (5 mg of K₁/day) does not protect against age-related decreasing bone density, but may protect against fractures and cancers, in postmenopausal women taking calcium and vitamin D supplements.

Menaquinone

Menatetrenone

Menatetrenone , also known as MK4, is a menaquinone compound used as a hemostatic agent and as adjunctive therapy for the pain of osteoporosis. It is marketed for the latter indication in Japan by Eisai Co., under the trade name Glakay....

 (vitamin K₂), but not phylloquinone

Phylloquinone

Phylloquinone is a polycyclic aromatic ketone, based on 2-methyl-1,4-naphthoquinone, with a 3-phytyl substituent.It is a fat-soluble vitamin that is stable to air and moisture but decomposes in sunlight. It is found naturally in a wide variety of green plants.-Terminology:It is often called...

 (vitamin K₁), intake is associated with reduced risk of CHD

Coronary heart disease

Coronary artery disease is the end result of the accumulation of atheromatous plaques within the walls of the coronary arteries that supply the myocardium with oxygen and nutrients. It is sometimes also called coronary heart disease...

 mortality

Death

Death is the permanent termination of the biological functions that sustain a living organism. Phenomena which commonly bring about death include old age, predation, malnutrition, disease, and accidents or trauma resulting in terminal injury....

, all-cause mortality and severe aortic calcification.

In a cohort study in Germany (11319 men, mean follow-up time 8.6y), Menaquinone intake was associated with decreased incidence of advanced prostate cancer.

Prevalence

The prevalence of vitamin K deficiency varies by geographic region.

For infants in the United States, vitamin K deficiency without bleeding may occur in as many as 50% of infants younger than 5 days old. Therefore, the Committee on Nutrition of the American Academy of Pediatrics recommends that 0.5 to 1.0 mg Vitamin K₁ be administered to all newborns shortly after birth.

Postmenopausal and elderly women in Thailand have high risk of Vitamin K₂ deficiency, compared with the normal value of young, reproductive females.
Current dosage recommendations for Vitamin K may be too low.

The deposition of calcium in soft tissues, including arterial walls, is quite common, especially in those suffering from atherosclerosis

Atherosclerosis

Atherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...

, suggesting that Vitamin K deficiency is more common than previously thought.