A graduate student conducting research on the association between vitamin D₃ supplementation and cancer is reviewing the abstract of a recently published journal article. The graduate student is interested in conducting further studies among individuals with BMI

Question

A graduate student conducting research on the association between vitamin D₃ supplementation and cancer is reviewing the abstract of a recently published journal article. The graduate student is interested in conducting further studies among individuals with BMI <25 kg/m². Which of the following statements regarding these individuals is best supported by the abstract?

Quizplus · Accepted Answer

Explanation: Based on the stratified analysis in the abstract, the estimated HR and 95% CI for the association between vitamin D₃ supplementation and metastatic cancer and cancer mortality among individuals with BMI <25 kg/m² were as follows: Metastatic cancer: HR = 0.63; 95% CI: 0.38-1.05 Cancer mortality: HR = 0.58; 95% CI: 0.39-0.86 The CIs for cancer mortality excluded the null value (HR = 1), suggesting there is a significant association between vitamin D₃ supplementation and cancer mortality in individuals with BMI <25 kg/m² (Choice D). In contrast, the CI for metastatic cancer included the null value, suggesting that vitamin D₃ supplementation is not associated with metastatic cancer (Choice B). Because the corresponding HR < 1, vitamin D₃ supplementation is associated with a significant decrease in the risk of cancer mortality. Therefore, individuals who have a BMI <25 kg/m² have a significantly lower risk of cancer mortality when they supplement their diets with vitamin D₃. In vitro studies suggest that vitamin D or its analogs may decrease cell proliferation; therefore, vitamin D supplementation has been evaluated in several trials regarding cancer prevention. However, different trials have yielded conflicting results, and supplementation is currently not recommended as a preventive measure. (Choice A) The abstract does not provide information about the association between BMI and cancer mortality; instead, it provides information about the association between vitamin D₃ supplementation and cancer mortality at different BMI levels. Educational objective: A hazard ratio (HR) <1 indicates that the exposure is associated with a decrease in the risk of an outcome. A confidence interval that excludes the null value (HR = 1) is statistically significant.

A Graduate Student Conducting Research on the Association Between Vitamin