Hip fractures reduced 16 to 33 percent by any amount of Vitamin D and Calcium – Oct 2019

Impact of Vitamin D Supplementation on Falls and Fractures – a Critical Appraisal of the Quality of the Evidence and an Overview of the available guidelines

Bone, https://doi.org/10.1016/j.bone.2019.115112
Marlene Chakhtoura 1 Nariman Chamoun 1 Maya Rahme 1v GhadaEl-Hajj Fuleihan 1

Highlights

• The effect of vitamin D supplementation, with or without calcium, on falls is inconsistent.
• Vitamin D and calcium (CaD) does not reduce fracture risk in community dwelling subjects.
• CaD reduces hip fracture by 16-33% in studies from all residencies combined.
• The evidence on vitamin D effects on skeletal outcomes has major challenges.
• Only rigorous high quality meta-analyses of homogenous studies can yield final conclusions.

Introduction
The beneficial effect of vitamin D supplementation on musculo-skeletal outcomes have been recently questioned and recommendations regarding supplementation vary widely. The aim of this paper is to systematically assess the quality of the evidence evaluating the effect of vitamin D supplementation on falls and fractures.

Methods
We conducted a systematic search in Medline, PubMed, and Embase and selected systematic reviews (SRs) / meta-analyses (MAs) of randomized controlled trials (RCTs) on vitamin D supplementation and falls or fracture, published between 2012 - 2018. We identified 5 MAs of RCTs on falls, 4 on fractures and 4 on both outcomes. We applied the critical appraisal tool “A MeaSurement Tool to Assess systematic Reviews” – AMSTAR- to assess the quality of the identified MAs.

Results
Vitamin D and calcium supplementation (CaD), compared to calcium only or placebo, may reduce the risk of falls, in institutionalized individuals and/or those from the community, but the data is inconsistent. The largest and most consistent evidence for a protective effect of CaD, compared to placebo or control, is in reducing the risk of hip fracture, by 16-33%, and any fracture, by 5-19%. This effect was demonstrated when combining trials in community-dwelling and institutionalized individuals, potentially driven by data from institutionalized individuals as shown in 3 SRs/MAs. Major limitations to the quality of the evidence include variability in the methodology of MAs, but more importantly, differences between trials in terms of subjects’ characteristics, vitamin D regimens, outcome definition and ascertainment, risk of bias, trial duration and/or low power. The quality of the included MAs was moderate to critically low.

Conclusions
While the effect on falls is inconsistent, CaD reduces the risk of fracture (hip and any fracture), as shown in meta-analyses pooling data of studies combining institutionalized and community individuals. The evidence is however limited by major shortcomings and heterogeneity.