A major way in which vitamin K contributes to bone health is through its rule as a cofactor in the carboxylation, or activation, of the bone formation marker osteocalcin. A low degree of osteocalcin carboxylation in the body has been related to osteoporosis. Any randomized, placebo/controlled, double blind study, postmenopausal women with osteopenia were given either 5 mg of vitamin K1 or a placebo daily, Even though the study was aimed at following the age-related decline in bone mineral density, additional significant observations were made.
The researchers noted that although the age-related decline in bone mineral density was not affected, an increased percentage of osteocalcin was carboxylated, indicating a lessening of osteoporotic activity. Furthermore, fewer women in the vitamin K1 group had fractures, and fewer had cancers.
In the treatment of osteoporosis, vitamin K supplementation will refer primarily to vitamin K2 (MK-7) and to a lesser degree, vitamin K1.
In a study on rats, it was shown that vitamin K2 (MK-7) improved the quality of bone to the point that the vertebral fractures were prevented, even though bone mass was not increased. In another study, vitamin K2 (MK-7) prevented the bone loss that would otherwise develop from the loss of hormone production in rats subjected to the removal of the ovaries.
In another study with rats without ovaries, vitamin K2 (MK-7) administration resulted in significant improved bone strength and less susceptibility to fractures.
In humans, low intake of vitamin K or low blood level of vitamin K, as well as of vitamin D, were found to be significant, an independent determinant of osteoporosis and bone fracture risk. Furthermore, the risk was found to be independent of any generalized malnutrition. A low dose (180 mcg daily) of vitamin K2 (MK-7) over a three-year period was found to decrease bone loss in postmenopausal women.
It would appear that vitamin K is not just an important part of an osteoporosis treatment regimen, but a mandatory one.
The lack of toxicity of vitamin K is nearly as impressive as its effectiveness in decreasing the incidence of osteoporotic fractures, preventing new ectopic calcification, and dissolving existing ectopic calcifications.
Vitamin K2 also has demonstrated no known toxicity or undesired side effects when administered to newborns or pregnant women.