Annweiler C, et al. – This paper appraised and quantitatively evaluated the link between 25–hydroxyvitamin D (25OHD) concentration with walking speed. Robust evidence was gained with regard to 25OHD concentrations exhibiting a positive correlation with walking speed, among adults.

Methods

• The findings were obtained from Medline search on June 2017, with no limit of date.
• The keywords used were MeSH terms “Vitamin D” OR “Vitamin D Deficiency” combined with “Gait” OR “Gait disorders, Neurologic” OR “Walking speed” OR “Gait velocity”.
• Fixed-effect meta-analyses computed:
• i) Mean differences in usual and fast walking speeds and Timed Up and Go test (TUG) between participants with severe vitamin D deficiency (≤25nmol/L) (SVDD), vitamin D deficiency (≤50nmol/L) (VDD), vitamin D insufficiency (≤75nmol/L) (VDI) and normal vitamin D ( > 75nmol/L) (NVD)
• ii) Risk of slow walking speed according to vitamin D status.
• Among the 243 retrieved studies, 22 observational studies (17 cross-sectional, 5 longitudinal) met the selection criteria.
• Enrollees ranged between 54 and 4,100 (0-100% female).

Results

• Slower usual walking speed was noted among candidates with hypovitaminosis D, with a clinically relevant difference compared with NVD of -0.18 m/s for SVDD, -0.08 m/s for VDD and -0.12 m/s for VDI.
• Similar findings were noted in terms of fast walking speed (mean differences -0.04 m/s for VDD and VDI compared with NVD) and TUG (mean difference 0.48 s for SVDD compared with NVD).
• A slow usual walking speed exhibited positive relation with SVDD (summary OR = 2.17[95%CI:1.52-3.10]), VDD (OR = 1.38[95%CI:1.01-1.89]) and VDI (OR = 1.38[95%CI:1.04-1.83]), using NVD as the reference.