Thursday, May 19, 2016
Vitamin K is a group of compounds that share a similar chemical structure and are classified as vitamin K1 (phylloquinone), vitamin K2 (menaquinone), and vitamin K3 (menadione). Phylloquinone is predominantly present in green, leafy vegetables, whereas menaquinone is synthesized by bacteria, and menadione is the synthetic form of vitamin K. Primary food sources of menaquinone are fermented foods such soy products.
The crucial role of Vitamin K in blood coagulation is well established. However, its role in the maintenance of bone health is presently under investigation. Recent studies have discovered the involvement of vitamin K as a coenzyme in the synthesis of osteocalcin, a protein derived from osteoblasts that is involved in bone formation. A study conducted in Japan correlated circulatory vitamin K2 levels to the regional variation in consumption of natto, suggesting a possible implication of vitamin K2 in hip fracture.
However, evidence for the association between vitamin K, osteocalcin, and bone health is contradictory. The National Osteoporosis Foundation does not support the use of vitamin K supplementation to prevent osteoporosis and fracture of the bones. This may be attributed to the fact that vitamin K supplementation may decrease the functional efficiency of drugs such as warfarin.
Future research may be directed towards the amount and form of vitamin K that is necessary for optimal bone health. It is important to clear the ambiguity about the diverse roles played by vitamin K in the normal functioning of the body.
News Source: Cunningham E. What Is Vitamin K2 and Does It Have an Impact on Bone Health?. Journal of the Academy of Nutrition and Dietetics. 2016 May;116(5):888.