Supplementation and the Risk of Fractures

Review the paper by Jackson et al., Calcium plus Vitamin D Supplementation and the Risk of Fracturesyto answer the following question. (Link to article: https://www.nejm.org/doi/10.1056/NEJMoa055218?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%20%200www.ncbi.nim .nih.gov) What were the limitations of this study? (Choose all that apply) Ca. There weren’t enough participants who adhered to the treatment, reducing the statistical significance of the study b. There may be selection bias c. This study has weak external validity Od. The individual effects of calcium and vitamin D cannot be separated e. This study has weak internal validity Of. The observed lack of efficacy is not aligned with a meta-analysis of similar clinical trials g. Baseline characteristics may differ between study groups h. There were no limitations