CRD Summary: This review found that there is a trend towards a reduced risk of falls associated with vitamin D treatment. Evidence relating to fracture risk was inconclusive. The conclusion about risk of falls is not well supported by the evidence presented, as no benefit was found for postmenopausal women and the review was not designed to apply to any other population group.

CRD Commentary: The review objective and inclusion criteria were unclear with respect to the participant group of interest. Consequently, nearly half of the primary studies included both men and women and were thus of unknown applicability to postmenopausal women. Relevant sources were searched for studies, but the search terms were not reported. No attempt was made to locate unpublished data and the search was restricted by language, so some studies might have been missed. Publication bias was not assessed. It is unclear whether steps were taken to minimise bias and error in the study selection, validity assessment and data extraction processes by having more than one reviewer make decisions independently. Although study validity was assessed, there were no details about the validity of individual RCTs (e.g. drop-out rates) and the validity assessment tool used was not designed for non-RCTs. Appropriate methods were used to pool studies and test for statistical heterogeneity, and potential sources of clinical and methodological heterogeneity were well addressed in the text. The poor reporting of review methods and lack of detail about study quality make it difficult to assess the reliability of the findings. Moreover, the authors’ conclusions are not supported by the evidence presented: no significant benefit from vitamin D was found for postmenopausal women and the review was not designed to apply to any other population group.