Vitamin K - Vitamin K Absorption and Dietary Need

Vitamin K Absorption and Dietary Need

Previous theory held that dietary deficiency is extremely rare unless the intestine (small bowel) was heavily damaged, resulting in malabsorption of the molecule. The other at-risk group for deficiency were those subject to decreased production of K₂ by normal flora, as seen in broad spectrum antibiotic use. Taking broad-spectrum antibiotics can reduce vitamin K production in the gut by nearly 74% in people compared with those not taking these antibiotics. Diets low in vitamin K also decrease the body's vitamin K concentration. Additionally, in the elderly there is a reduction in vitamin K₂ production.

Recent research results also demonstrate that the small intestine and large intestine (colon) seem to be inefficient at absorbing vitamin K. These results are reinforced by human cohort studies, where a majority of the subjects showed inadequate vitamin K amounts in the body. This was revealed by the presence of large amounts of incomplete gamma-carboxylated proteins in the blood, an indirect test for vitamin K deficiency. And in an animal model MK4 was shown to prevent arterial calcifications, pointing to its potential role in cardiovascular disease prevention. In this study vitamin K₁ was also tested and shown not to prevent arterial calcifications.