Bone Abstracts

This study is focused on the effects of the synergic use of vitamins D and K on human osteoblasts primary cultures derived from osteoporotic and normal patients. The aim of this work is the evaluation of the different cellular behaviour in response to the lipophilic vitamins stimulation. We included 20 osteoporotic and 20 control patients in age between 35 and 50 and in age between 55 and 85. All patients gave informed consent for using bone samples as a source of bone cells. DXA at lumbar spine and femur, in terms of BMD, were perfomed.Changes in osteocalcin and alcaline phosphatase production were also evaluated in cells cultures. The response of osteoblasts to Vitamin D appears to depend on the stage of osteoblast maturation, with preferential induction of the catabolic factor, receptor activator of nuclear factor κB ligand (RANKL) and had pro-anabolic activity by enhancing the production of matrix vesicles and mineral deposition.

Vitamin K is an essential cofactor for the formation of GLA (γ-carboxyglutamic acid) residues in proteins, important not only for blood coagulation but also for calcified tissues; on the other hand vitamin D (1.25-dihydroxy-vitamin D3), is critical for the regulation of serum calcium and phosphorus levels that in turn support bone mineralization and neuromuscular activity. It is well known that vitamin D can stimulate the metabolic activity of human osteoblasts in vitro therefore it is used on osteoporotic patients. We are evaluating the results on vitamins D and K cross action treatment over these subjects.