Bone 101

In the fall I attended a lecture on osteoporosis. The presentation was thorough, giving all the statistics and risk of fracture rates and mortality, as well as discussing conventional treatment. However, what caught my attention was the presenter’s elucidation of bone physiology and a new way of looking at osteoporosis treatment.

While the nature of bone is to be strong and firm, it also needs to be flexible. The elastic quality of bone allows it to shorten when stress is applied, but return to its original length when the stress is removed. Generally the focus of therapy is on increasing bone density, but therapy should also encourage flexibility. The following website has a fun interactive bit to illustrate this concept. http://courses.washington.edu/bonephys/Gallery/biomechanics.swf

Accordingly, the treatment plan presented at the lecture addressed the idea of maintaining bone elasticity through supporting the formation of bone collagen, as well as quality bone. Osteocalcin, a protein found in bone, undergoes a specific reaction called g-carboxylation. This chemical reaction triggers osteocalcin to bind minerals within the bone matrix and is dependent on vitamin K. Research has found an association between an increase of under-carboxylated osteocalcin (ucOC), low levels of vitamin K and an increased risk of hip fracture in older women. http://www.ncbi.nlm.nih.gov/pubmed/9062471?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=7 ;

http://www.springerlink.com/content/26hjfngbhhme8m0w/

Further, there are different forms of vitamin K, vitamin K1 and K2. In turn, vitamin K2 has two forms, menatetrenone (MK4) and menaquinone-7 (MK7). MK4 and MK7 have been researched for their activity of inhibiting osteoclast and inducing osteoblast formation resulting in an increase in normal bone modeling. The role of the different forms of vitamin K in growth of bone connective tissue is not clear. However, studies using these forms of vitamin K2 have resulted in lower fracture rates, supposing vitamin K is contributing to more elasticity to the bone architecture.

Some of my colleagues voiced concern about the amount of vitamin K presented as treatment (45 mg/d) and that there needs to be more research to determine the safety. http://www.ncbi.nlm.nih.gov/pubmed/10750566?itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum&ordinalpos=126.

However, it appears that making sure vitamin K levels are optimal in the body is a key factor in bone health.

Sherry LaBeck, ND