Vitamin D and Skeletal Muscle: Current Concepts From Preclinical Studies

Abstract

Muscle weakness has been recognized as a hallmark feature of vitamin D deficiency for many years. Until recently, the direct biomolecular effects of vitamin D on skeletal muscle have been unclear. Although in the past, some reservations have been raised regarding the expression of the vitamin D receptor in muscle tissue, this special issue review article outlines the clear evidence from preclinical studies for not only the expression of the receptor in muscle but also the roles of vitamin D activity in muscle development, mass, and strength. Additionally, muscle may also serve as a dynamic storage site for vitamin D, and play a central role in the maintenance of circulating 25-hydroxy vitamin D levels during periods of low sun exposure.

Body Composition, Eicosapentaenoic Acid, and Vitamin D are Associated with Army Combat Fitness Test Performance

“…Beyond the well-established effects on bone and calcium health, VITD participates in many extraskeletal physiological and pathological processes via the ubiquitous vitamin D receptor [ 44 ], including muscle protein turnover and skeletal muscle repair, recovery, and regeneration [ 21 ]. Unfortunately, recent studies have shown that military personnel exhibit high levels of VITD insufficiency with estimates ranging from 57% to 86.1% [ 12 , 45 ].…”

“…Additionally, studies monitoring the physiological impact of intense military and athlete training have shown that O3i and VITD status significantly decreases from pre- to post-training [ 18–20 ]. Incidentally, blood levels of long-chain omega-3 polyunsaturated fatty acids (LC n-3 PUFA), EPA and DHA, and VITD have been shown to be powerful modulators of skeletal muscle physiology [ 21 , 22 ] and are positively associated with muscular performance in healthy adults and athletes [ 15 , 23 , 24 ]. This is especially relevant for Army personnel transitioning from an endurance-based test (APFT) to a test that includes other combat-relevant metrics such as strength, power, speed, and agility (ACFT).…”

Vitamin D Metabolites Are Associated With Musculoskeletal Injury in Young Adults: A Prospective Cohort Study

“…(3,4) A meta-analysis of randomized controlled trials concluded vitamin D and calcium supplementation reduces fracture risk in older men and women (mean age 66 years). (5) Emerging evidence suggests a role for vitamin D in promoting skeletal muscle repair and remodeling (6,7) and tendon healing. (8) In young adults, and physically active individuals in particular, the relationship between vitamin D status and overuse injury to bone, muscle, or connective tissues is unclear.…”

“…Bone stress injuryDuring 12 weeks of training, 5.6% of participants sustained ≥1 lower body bone stress injury. The incidence of lower body bone stress injury was higher in women undertaking standard training compared with men undertaking Officer training, and higher in men undertaking Infantry training compared with men undertaking Officer training ( p < 0.05; Table3).Lost training daysOveruse musculoskeletal injuryEach lower body overuse musculoskeletal injury resulted in a median (interquartile range [IQR]) 6(3)(4)(5)(6)(7)(8)(9)(10)(11)(12) lost training days.…”

Association between sarcopenia and risk of osteoarthritis among the US adults

“…In the past, the underlying mechanisms of sarcopenia has mainly focused on malnutrition, obesity, unnormal insulin signal, and Vitamin D de ciency [5][6][7] . Recently, low-grade local and systemic in ammation has been reported as leading to the development of sarcopenia.…”