Maintaining Muscle Strength in Crohn’s Disease: Can a Vitamin D Daily Keep Muscle Loss Away?

Abstract

Intact skeletal muscle strength and function are underappreciated aspects of normal human functioning. Moreover, it is widely accepted that muscle strength is a predictor of physical disability in patients with chronic diseases similar to inflammatory bowel disease (IBD, comprising Crohn’s disease and ulcerative colitis) such as rheumatoid arthritis [1], but also in normal ageing where healthy persons with a greater reserve in muscle function appear to have longer life spans [2]. Despite the intuitive importance of skeletal muscle in daily living, and the recent interest in the characterization of disability in patients with IBD [3], hitherto there are few studies examining muscle dysfunction in IBD [4]. In this issue, Salacinski et al. [5] have objectively demonstrated reduced lower limb muscle strength in subjects with Crohn’s disease (CD) compared to healthy controls, confirming the work of previous studies [6, 7]. However, the study was unable to show that this reduced strength was directly attributable to lower vitamin D (25(OH) or vitamin D3) levels in CD subjects as originally hypothesized. This exemplifies the complexity of teasing out potential causative and/or contributing factors in the reduced muscle strength and performance seen in CD. Delving Further into Vitamin D