Over the last few weeks, two of my golfing buddies incidentally mentioned to me that their doctors took them off their bisphosphonate bone drugs because the drugs were not helping stabilize bone. No surprise there — if the drugs weren’t working, of course their doctors were right to stop the treatment.
The interesting part was that right after going off the drugs, both of my friends had gained bone density.
Of course, my first question to both women was, “What changes did you make that could have helped you to build bone?” As I probably should have expected, both women reported that after being taken off the drugs, each of them had had their vitamin D levels tested for the very first time. Both women were found to be vitamin D deficient and had begun taking supplemental vitamin D on a regular basis… and that’s most likely the reason they built new bone.
It seems to defy common sense that vitamin D testing should come several years aftertreatment with bone drugs, but unfortunately my friends’ experience is typical. And it has a profound impact on how well the drugs work. New research by Carmel et al., released at the 2011 annual ASBMR meeting, reported that “[w]omen whose mean level of serum 25 hydroxy vitamin D (25[OH]D) was at least 33 ng/mL were almost five times more likely to benefit from bisphosphonates than those whose levels fell below that cutoff.” In other words, a sub-adequate level of vitamin D, defined as any level below 33 ng/mL, was directly correlated with failure of the drugs to provide a benefit.
Now, many doctors still consider vitamin D readings in the high 20s or low 30s to be adequate. Even more troubling, recent Institute of Medicine findings declared vitamin D levels of 20 ng/mL or greater to be adequate. But this research shows that at such low levels, bone has little or no ability to renew itself — even in the presence of powerful drugs that put a halt to osteoclast activity.
Ultimately, this study shows that everyone — even those on bone drugs! — needs truly adequate vitamin D — that is, a level greater than 33 ng/mL — in order to absorb calcium and protect bone. It’s frustrating to realize just how long it has taken medical science to recognize this basic fact. Indeed, I would take this further and state that everyone also needs the full complement of all 20 key bone nutrients.
How long it will take researchers to finally grasp the idea that our skeleton needs a full array of nutrients, just as does the entire body?
References:
Carmel, A., et al. 2011. The 25(OH)D level associated with a favorable response is >33 ng/mL. ASBMR Abstract 1137. Institute of Medicine (IOM) Dietary Reference Intakes for Calcium and Vitamin D. November 20, 2010.