Calcium and vitamin D supplementation and loss of bone mineral density in women undergoing breast cancer therapy

Abstract

An unintended consequence of breast cancer therapies is an increased risk of osteoporosis due to accelerated bone loss. We conducted a systematic review of calcium and/or vitamin D (Ca±D) supplementation trials for maintaining bone mineral density (BMD) in women with breast cancer using the “before-after” data from the Ca±D supplemented comparison group of trials evaluating the effect of drugs such as bisphosphonates on BMD. Whether Ca±D supplements increase BMD in women undergoing breast cancer therapy has never been tested against an unsupplemented control group. However, results from 16 trials indicate that the Ca±D doses tested (500-1500 mg calcium; 200-1000 IU vitamin D) were inadequate to prevent BMD loss in these women. Cardiovascular disease is the main cause of mortality in women with breast cancer. Because calcium supplements may increase cardiovascular disease risk, future trials should evaluate the safety and efficacy of Ca±D supplementation in women undergoing breast cancer therapy.

Vitamin D supplementation review and recommendations for women diagnosed with breast or ovary cancer in the context of bone health and cancer prognosis/risk

“…These factors can help explain Datta and Schwartz [57] negative conclusions about the review of vitamin D supplementation trials with breast cancer women, indicating that 200-1000 IU vitamin D (5-25 g) were inadequate to prevent BMD:…”

“…2. Most importantly Datta and Schwartz [57] analysis had no unsupplemented control group to be able to properly conclude supplementation had no positive effect in protecting BMD. Even if supplementation did not avoid an absolute decrease in BMD values, an attenuation of BMD decrease could not be ruled out.…”

“…Datta and Schwartz [57] carried a review of clinical trials with calcium and vitamin D supplementation done with women undergoing breast cancer therapy. This review concluded that 500-1500 mg calcium and 200-1000 IU (5-25 g) vitamin D were inadequate to prevent BMD because there were still BMD losses in all studies despite supplementation, although admitted that there was a lack of an unsupplemented comparison group.…”

Management of Aromatase Inhibitor-Associated Bone Loss (AIBL) in postmenopausal women with hormone sensitive breast cancer: Joint position statement of the IOF, CABS, ECTS, IEG, ESCEO, IMS, and SIOG

“…For other postmenopausal women receiving AI therapy, a dose of at least 800 (and up to 2000) IU of vitamin D every day is recommended to maintain replete levels. It is important to note, that a recent meta-analysis has underlined that the use of Vitamin D+/-calcium supplementation alone has been shown to be ineffective for fracture risk prevention in women with breast cancer (Evidence level 1 A) [125].

Fig. 1Recommended algorithm for managing bone health in women receiving aromatase inhibitor (AI) therapy for breast cancer.

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Cancer‐ and Chemotherapy‐Induced Musculoskeletal Degradation

“…No data have been published on the incidence and severity of either hyper‐ or hypocalcemia in patients with early stage cancer who are not receiving bone‐modifying agents. Two systematic reviews looking at the effect of calcium and vitamin D supplementation on bone health in early stage breast and prostate cancer patients receiving hormone therapy found the current recommended guidelines to be inadequate to have an effect on bone health . Further studies are required to establish the efficacy of and guidelines for calcium and vitamin D consumption or supplementation on bone health in this population.…”