Article

The Roles of Vitamin D in Skeletal Muscle: Form, Function, and Metabolism.

and Department of Endocrinology and Diabetes (J.E.G.), Westmead Hospital, Sydney, New South Wales 2145, Australia.
Endocrine reviews (Impact Factor: 19.76). 11/2012; DOI: 10.1210/er.2012-1012
Source: PubMed

ABSTRACT Beyond its established role in bone and mineral homeostasis, there is emerging evidence that vitamin D exerts a range of effects in skeletal muscle. Reports of profound muscle weakness and changes in the muscle morphology of adults with vitamin D deficiency have long been described. These reports have been supplemented by numerous trials assessing the impact of vitamin D on muscle strength and mass and falls in predominantly elderly and deficient populations. At a basic level, animal models have confirmed that vitamin D deficiency and congenital aberrations in the vitamin D endocrine system may result in muscle weakness. To explain these effects, some molecular mechanisms by which vitamin D impacts on muscle cell differentiation, intracellular calcium handling, and genomic activity have been elucidated. There are also suggestions that vitamin D alters muscle metabolism, specifically its sensitivity to insulin, which is a pertinent feature in the pathophysiology of insulin resistance and type 2 diabetes. We will review the range of human clinical, animal, and cell studies that address the impact of vitamin D in skeletal muscle, and discuss the controversial issues. This is a vibrant field of research and one that continues to extend the frontiers of knowledge of vitamin D's broad functional repertoire.

0 Bookmarks
 · 
137 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Sarcopenia and osteoporosis are two sides of the same coin. They represent different aspects of the same age-related process of musculoskeletal atrophy and together culminate in falls, fractures, deconditioning, and increased mortality in older individuals. However, the current therapeutic approach to the prevention of minimal trauma fracture is unilateral and focuses solely on bone. In theory, an integrated approach that recognizes the interaction between muscle and bone could break the vicious cycle of their combined involution and more effectively minimize falls/fractures. In this review, signaling pathways and cross-talk mechanisms that integrate bone/muscle, and the emergence of novel therapies that exploit these pathways to target osteoporosis/sarcopenia will be discussed. In broad terms, these agents act on nuclear receptors (e.g., VDR, AR) or transmembrane receptors (e.g., activins, GH/ IGF-1) expressed in muscle and bone, and seek to alter biologic responses to musculoskeletal aging, loading, and injury. Challenges in the development of these dual bone– muscle therapies, early clinical trials examining their safety/efficacy, and novel targets that hold promise in the reversal of musculoskeletal aging will be discussed.
    Calcified Tissue International 01/2015; · 2.75 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Scurvy and rickets are largely considered historical diseases in developed countries. However, deficiencies in vitamins C and D are re-emerging due to increased consumption of processed foods and reduced fresh foods in the Western diet, as well as to an indoor sedentary lifestyle away from sun exposure. These dietary and lifestyle factors also predispose one to diabetes and metabolic syndrome. Our understanding of the potential roles of vitamin C (an antioxidant) and vitamin D (a biologically active hormone) in disease is increasing. In this review, we present observational, interventional, and mechanistic studies that examine the potential links between vitamins C and D in reversing defects in glucose homeostasis and the prevention of type 2 diabetes. Studies suggest an association between vitamin C deficiency and diabetes. An association between vitamin D and insulin resistance has been well described; however, the role of vitamin C and D supplementation in diabetes and its prevention requires further controlled trials.
    Nutrition and Dietary Supplements 02/2015; 7:21-28.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Scurvy and rickets are largely considered historical diseases in developed countries. However, deficiencies in vitamins C and D are re-emerging due to increased consumption of processed foods and reduced fresh foods in the Western diet, as well as to an indoor sedentary lifestyle away from sun exposure. These dietary and lifestyle factors also predispose one to diabetes and metabolic syndrome. Our understanding of the potential roles of vitamin C (an antioxidant) and vitamin D (a biologically active hormone) in disease is increasing. In this review, we present observational, interventional, and mechanistic studies that examine the potential links between vitamins C and D in reversing defects in glucose homeostasis and the prevention of type 2 diabetes. Studies suggest an association between vitamin C deficiency and diabetes. An association between vitamin D and insulin resistance has been well described; however, the role of vitamin C and D supplementation in diabetes and its prevention requires further controlled trials.
    Nutrition and Dietary Supplements 02/2015; 2015(7):21-28.

Full-text

Download
55 Downloads
Available from
May 29, 2014