A Systematic Review of the Role of Vitamin D on Neuromuscular Remodelling Following Exercise and Injury

Abstract

to systematically review the available evidence of the role of vitamin D on neuromuscular remodelling following exercise conditioning, exercise- or experimentally induced injury. We searched Medline (OVID platform), PubMed, Embase and Web of Science for randomised controlled trials (RCTs) including measures of neuromuscular function, injury and/or inflammation; a physiologically stressful intervention involving exercise conditioning, exercise- or experimentally induced injury and; vitamin D supplementation. Nine RCTs met the inclusion criteria. Significant heterogeneity of methodological approaches and outcomes meant that meta-analysis of data was limited. Qualitative findings indicated that vitamin D may be an effective accelerant of neuromuscular remodelling in animal models (24-140 % improved recovery vs. control); the effects in humans are inconclusive and likely influenced by baseline vitamin D and supplementation strategy. Results of the meta-analyses indicated no effect of vitamin D supplementation on muscle strength adaptation following resistance training [standardised mean difference (SMD): 0.74, P = 0.42] or muscle damage (SMD: -0.03, P = 0.92), although inflammatory markers were elevated in the latter (SMD: 0.56, P = 0.04). Data from animal models offer promising and plausible mechanisms for vitamin D as an agent for neuromuscular adaptation. Further high-quality research is needed to offer clearer insight into the influential role of vitamin D in human populations.

Vitamin D in amyotrophic lateral sclerosis

“…Similarly to our results, studies in healthy subjects indicated that vitamin D intake did not improve muscle tropism and strength (Agergaard et al, 2015). The ability of the neuromuscular system to remodel in response to resistance rehabilitation training or following injury still remains to be understood (Minshull et al, 2016). Nevertheless, other Authors reported a high incidence of vitamin D deficiency in patients with ALS, and also found, at the 9-month follow-up, a slower decline in ALS-FRS-R scores in 20 patients treated with 2,000 IU of cholecalciferol per day compared with patients who did not take the same treatment (Karam et al, 2013).…”

“…Moreover, vitamin D applied on motoneurons cultured in vitro seems to potentiate the effects of glial-and brainderived neurotrophic growth factors, protecting cells from Fas-induced cell death (Camu et al, 2014). Although ev- idence from the animal models suggests an effect of supplemental vitamin D on ALS, these positive results may not always extend to humans (Minshull et al, 2016;Blasco et al, 2015;Yang et al, 2016). Similarly to our results, studies in healthy subjects indicated that vitamin D intake did not improve muscle tropism and strength (Agergaard et al, 2015).…”

Association Between Preoperative Vitamin D Status and Short-Term Physical Performance after Total Hip Arthroplasty: A Prospective Study

“…Vitamin D is positively associated with muscle function, muscle strength, and physical performance [6][7][8]. Furthermore, a meta-analysis of 13 RCTs reported a beneficial effect of vitamin D supplementation (800-100 IU/day) on measures of muscle strength and balance in individuals aged 60 years and older [9].…”

“…A metaanalysis of 30 RCTs in individuals of all ages showed a significant positive effect of vitamin D supplementation on muscle strength, which was most evident in people with a 25-hydroxyvitamin D 3 (25[OH]D 3 ) level < 30 nmol/L and in those who were older than 65 years [10]. Vitamin D plays a direct role on muscle quality via activation of the vitamin D receptors, which are involved in muscle protein synthesis and muscle growth [6,8]. Moreover, vitamin D is indirectly related to muscle function via the calcium-phosphate balance [6,8].…”

“…Vitamin D plays a direct role on muscle quality via activation of the vitamin D receptors, which are involved in muscle protein synthesis and muscle growth [6,8]. Moreover, vitamin D is indirectly related to muscle function via the calcium-phosphate balance [6,8]. Calcium is involved in the contraction of muscle, whereas phosphate is required for the structural and metabolic needs of the muscle cell [6,11].…”