Rosendahl-Riise et al  carried out a meta-analysis of the impact of vitamin D supplements on strength and mobility (assessed by the timed-up-and-go; TUG) in free-living older adults. Contrary to the findings from a previous meta-analysis , the authors surprisingly reported, in the abstract and conclusion, an overall negative effect of vitamin D on mobility. However, Figure 3 shows that the overall TUG score mean difference is in favor of the intervention; opposite to having deteriorated, the score improved by 0.31 seconds (i.e. less time to complete the test).
The meta-analysis by Rosendahl-Riise et al has generated interest and is an important contribution to the field of vitamin D and musculoskeletal health as it may inform guiding recommendations. Therefore, the erroneous data interpretation as stated in the abstract as well as in the conclusion should be corrected.
The author did not declare any conflicts of interest.
Anne-Julie Tessier, RD
School of Human Nutrition, McGill University
Research Institute, McGill University Health Center
Montreal, QC H4A 3J1
1. Rosendahl-Riise, H.; Spielau, U.; Ranhoff, A.H.; Gudbrandsen, O.A.; Dierkes, J. Vitamin d supplementation and its influence on muscle strength and mobility in community dwelling older persons: A systematic review and meta-analysis. J Hum Nutr Diet 2017, 30, 3-15. DOI: 10.1111/jhn.12394.
2. Muir, S.W.; Montero-Odasso, M. Effect of vitamin d supplementation on muscle strength, gait and balance in older adults: A systematic review and meta-analysis. J Am Geriatr Soc 2011, 59, 2291-2300. DOI: 10.1111/j.1532-5415.2011.03733.x.
Dear Ms Tessier
Thank you for bringing the above issues to our attention. We have passed on your letter to the authors of the paper, who have provided a corrigendum to their paper. We will be publishing this in the very near future and a link will be provided here.