Bone Risk in Thyroid Treatment

How much bone risk already?

Most women have probably already heard enough about osteoporosis to know whether they really need to worry about it. Most women do have to worry, at least here in the United States. Here’s a reminder of the factors that affect your risk: good to the right, bad to the left as you go down. Not having a “good” factor means you have risk on that basis.


(from the remarkable Dr. Susan Ott of the University of Washington).

Evaluating bone risk from thyroid hormone

Here are two sets of information for evaluating the risk of hyperthyroidism for your bones. Both of these should be reassuring that the risk to bone is either not a factor at all, or at least smaller than posed by other commonly-used treatments.

1. A literature review by a psychiatrist deeply invested in understanding thyroid in bipolar disorders

Dr. Tam Kelly, in Fort Collins, Colorado, has looked at the entire literature on the role of thyroid treatment in mood disorders as closely as anyone could. He has published case reports on well over 100 patients on thyroid treatments.  He concludes:

High dose thyroid does not appear to be a significant risk factor for osteoporosis while other widely employed psychiatric medications do pose a risk. Psychiatrists are uniquely qualified to do the risk-benefit analyses of high dose thyroid for the treatment of bipolar I, bipolar II and bipolar NOS. Other specialties do not have the requisite knowledge of the risks of alternative medications or of the mortality and morbidity of the bipolar disorders to do a full risk benefit analysis.

2. An older but similar opinion from Don Klein, a well-known psychiatrist who has reviewed this issue extensively — and others.

Here is Dr. Klein in an email discussion of the issue with colleagues ( if you want to read the whole thing, pretty technical but including the similar opinions of other doctors, click here) :

My conclusion

The stakes involved are very high:  if we find out in 10 years that bone density really is decreased by high-dose thyroid, it’s too late for women who were already at risk for osteoporosis and now have more severe bone loss. So despite the reassurances from these authorities, I think we still have to keep in mind the possibility that high-dose thyroid might harm bone density. I’d still use it, even in a thin caucasian woman smoker (high risk for osteoporosis), but I’d figure that bone safety is not fully established, and factor that into the discussion of treatment options.

At minimum though, even woman at very high risk for osteoporosis could try high-dose thyroid and find out if it worked, and how well.  Only if it works great does the whole bone story become relevant at all. One can find out first, then compare risks and benefits of other approaches.