Yes / Evidence suggests vitamin D3 (VD) supplementation can reduce accumulation of adipose tissue and inflammation and promote myogenesis in obese individuals, and thus could mitigate obesity-induced reductions in skeletal muscle (SkM) contractility. However, this is yet to be directly investigated. This study, using the work-loop technique, examined effects of VD (cholecalciferol) supplementation on isolated SkM contractility. Female mice (n = 37) consumed standard low-fat diet (SLD) or high-fat diet (HFD), with or without VD (20,000 IU/kg-1 ) for 12 weeks. Soleus and EDL (n = 8-10 per muscle per group) were isolated and absolute and normalized (to muscle size and body mass) isometric force and power output (PO) were measured, and fatigue resistance determined. Absolute and normalized isometric force and PO of soleus were unaffected by diet (P > 0.087). However, PO normalized to body mass was reduced in HFD groups (P 0.588). HFD reduced EDL isometric stress (P = 0.048) and absolute and normalized PO (P 0.493). Cumulative work during fatiguing contractions was lower in HFD groups (P 0.060). This study uniquely demonstrated that high-dose VD had limited effects on SkM contractility and did not offset demonstrated adverse effects of HFD. However, small and moderate effect sizes suggest improvement in EDL muscle performance and animal morphology in HFD VD groups. Given effect sizes observed, coupled with proposed inverted U-shaped dose-effect curve, future investigations are needed to determine dose/duration specific responses to VD, which may culminate in improved function of HFD SkM. NEW FINDINGS: What is the central question of this study? Can vitamin D supplementation alleviate detrimental effects of high-fat diet (HFD) consumption on contractile performance of isolated skeletal muscles? What is the main finding and its importance? The present study is the first to examine the synergistic effects of HFD consumption and vitamin D supplementation on the contractile performance of isolated skeletal muscle. These findings suggest high dose vitamin D has limited effects on force, power or fatigue resistance of isolated mouse soleus and extensor digitorum longus.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/19775 |
| Date | 05 January 2024 |
| Creators | Shelley, S.P., James, Rob S., Eustace, S.J., Eyre, E.L.J., Tallis, J. |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, Published version |
| Rights | © 2023 The Authors. Experimental Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited., CC-BY |
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