Association of calcium and vitamin D supplementation with cancer incidence and cause-specific mortality in Black women: Extended follow-up of the Women's Health Initiative calcium-vitamin D trial.

Low circulating vitamin D levels are more prevalent in Black than White individuals. We analyzed the Women's Health Initiative (WHI) calcium plus vitamin D (CaD) randomized clinical trial extended follow-up data to evaluate associations between calcium plus vitamin D supplementation and incident cancer, cardiovascular disease (CVD), and cause-specific mortality endpoints among Black women. Intent-to-treat analysis was performed. Among 3325 Black women in the CaD trial who were randomized into either daily calcium (1000 mg of calcium carbonate) plus vitamin D (400 IU D3) or placebos for an average of 7 years, there were 813 deaths, 588 incident cancers, and 837 CVD events during an average of 15.7 years of follow up (52 230 total person-years). Using Cox's proportional hazards models, we calculated hazard ratios and their confidence intervals for outcomes ascertained during the trial period, posttrial follow-up period and overall periods combined. We found that total mortality, cause-specific mortality, and total cancer incidence were almost identical between CaD and placebo groups. These results suggest that calcium plus vitamin D supplementation does not reduce risks of cancer, CVD, or other major causes of death in Black women overall and, thus, other medical, behavioral or social interventions should be considered to narrow health disparities related to these outcomes. However, other finer endpoints, such as colorectal cancer, warrants further investigation.

Physical activity and quality of life in African American cancer survivors: The Detroit Research on Cancer Survivors study.

BACKGROUND: The benefit of regular exercise in improving cancer outcomes is well established. The American Cancer Society (ACS) released a recommendation that cancer survivors should engage in at least 150 minutes of moderate to vigorous physical activity (PA) per week; however, few report meeting this recommendation. This study examined the patterns and correlates of meeting ACS PA recommendations in the Detroit Research on Cancer Survivors (ROCS) cohort of African American cancer survivors. METHODS: Detroit ROCS participants completed baseline and yearly follow-up surveys to update their health and health behaviors, including PA. This study examined participation in PA by select characteristics and reported health-related quality of life (HRQOL) as measured with the Functional Assessment of Cancer Therapy and Patient-Reported Outcomes Measurement Information System instruments. RESULTS: Among the first 1500 ROCS participants, 60% reported participating in regular PA, with 24% reporting ≥150 min/wk. Although there were no differences by sex, prostate cancer survivors were the most likely to report participating in regular PA, whereas lung cancer survivors were the least likely (P = .022). Survivors who reported participating in regular PA reported higher HRQOL (P < .001) and lower depression (P = .040). CONCLUSIONS: Just 24% of African American cancer survivors reported meeting the ACS guidelines for PA at the baseline, but it was encouraging to see increases in activity over time. Because of the established benefits of regular exercise observed in this study and others, identifying and reducing barriers to regular PA among African American cancer survivors are critical for improving outcomes and minimizing disparities.