Like all (or most) prostate cancer docs, I have routinely recommended calcium and vitamin D supplements for men going on androgen deprivation therapy (ADT, “hormone treatment”). The reason for this is that many studies show that men, just like their wives/girlfriends, start losing calcium from their bones as soon as testosterone levels drop – the equivalent of menopause and loss of estrogen in women. Of course, medical history is filled with examples of well-meaning interventions for patients that actually don’t work, even though they seem logical. One of the more commonly cited examples is the Vineberg procedure, in which cardiac surgeons re-routed arteries from the chest wall into the left ventricle in patients with coronary artery disease. Makes a lot of sense – the heart muscle isn’t getting enough blood, resulting in angina, so “fix it”. The problem is that it was never properly studied, and when it was, it didn’t work any better than sham operations in reducing angina. There may have been some benefit, but by the time proper studies were done, bypass grafts had overtaken the approach, and now this has been replaced in many cases by stents.
So back to the Vitamin D and Calcium story. An article appearing this week has suggested that our recommendations for calcium and vitamin D supplements are similarly poorly studied. They make sense, but the author appropriately raises questions as to what we actually know verses what seems logical in this paper in “The Oncologist”:
“CONCLUSIONS: Calcium and vitamin D supplements are widely prescribed to men with prostate cancer undergoing ADT. Whether supplementation of men undergoing ADT with calcium and/or vitamin D results in a higher BMD than in those with no supplementation has not been tested. Available clinical trial data regarding supplemental calcium at 500–1,000 mg/day and vitamin D at 200 –500 IU/day indicate that these regimens are inadequate to prevent BMD loss. Calcium supplements have been implicated in greater risks for cardiovascular disease and advanced prostate cancer. Thus, clinical trials to determine the risk–benefit ratio of calcium and vitamin D supplementation in men undergoing ADT for prostate cancer are urgently needed. Key safety endpoints in such trials should include markers of prostate cancer growth, for example, PSA and PSA velocity, as well as surrogate markers of cardiovascular disease.”
For now, I don’t think I will change my recommendations, and like the articles on coffee drinking, or alcohol intake on heart disease and everything else that goes wrong as we age, there will no doubt be lots of counterpoints. The “vitamin D believers” all will tell us that we need to be taking even more vitamin D and the evidence that vitamin D might slow the development of prostate cancer is reasonably solid. In any case, if you have significant heart disease, this article might be something to discuss with your cardiologist, if not your oncologist.