Vitamin K deficiency

Vitamin K deficiency is a form of avitaminosis resulting from insufficient vitamin K.

Vitamin K-deficiency may occur by disturbed intestinal uptake (such as would occur in a bile duct 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. Lack of control of the three processes mentioned above may lead to the four following: 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. The deposition of calcium in soft tissues, including arterial walls, is quite common, especially in those suffering from atherosclerosis, suggesting that Vitamin K deficiency is more common than previously thought. Menaquinone, but not phylloquinone, intake is associated with reduced risk of CHD mortality, 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.

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.

According to a study published in the October 14 2008 edition of PLoS Medicine, Vitamin K does not protect against age-related decreasing bone density, but may protect against fractures and cancers in postmenopausal women.