Are Vitamin D And Calcium Supplements Really Effective?
According to an article published in the July issue of the journal The oncologist, vitamin D and calcium supplements do not prevent bone loss, as was believed. Epidemiologists from at Wake Forest Baptist Medical Center have studied 12 clinical trials and the guidelines that recommend supplements of vitamin D and calcium and found that they did not bring any benefit. Moreover, it seems these supplements are harmful as they increase the cardiovascular and prostate cancer risk.
Vitamin D and calcium supplements have been widely recommended for patients who have followed androgen deprivation therapy (ADT). Androgen deprivation therapy is indicated for patients with advanced prostate cancer to stop tumor growth. To combat one of the adverse effects of androgen deprivation therapy, that is osteoporosis, patients are prescribed calcium and vitamin D supplements. Mridul Datta, Ph.D., co-author of the study and a postdoctoral fellow who works with Schwartz at Wake Forest Baptist, noted that in this context prescribing these supplements seemed so logical that no one questioned their effectiveness.
After carefully analyzing the clinical trials and guidelines, epidemiologists have realized that the 500 to 1000 mg of calcium and 200 to 500 IU of vitamin D per day did not prevent bone loss in men. Moreover, the fact that some studies have found an association between high calcium intake and risk of heart disease and prostate cancer is alarming. Gary G. Schwartz, Ph.D., who is a nationally-recognized prostate cancer epidemiologist at Wake Forest Baptist and lead author of the study, pointed out that these findings must be verified by further studies. Furthermore, Schwartz believes that scientists should do a study to compare not only the potential benefits of calcium and vitamin D supplements but also potential risks, such as cardiovascular risk and risk of prostate cancer.
The role of vitamin D supplements in different situations is, however, unclear. Low levels of vitamin D vitamin is associated with several diseases such as osteoporosis, multiple sclerosis, tuberculosis and cancer. However, it seems that supplements are not useful in patients with these diseases. Regarding the role of vitamin D supplements in cancer, there is still no significant evidence to justify their use.
As for calcium, there have been studies that have suggested that calcium supplements, with or without vitamin D, increase cardiovascular risk, especially risk of myocardial infarction. It seems that high levels of calcium stimulates vascular calcification and increases mortality among those with kidney failure.