Electromyography in nutritional osteomalacic myopathy.

Abstract

SYNOPSIS Electromyographic studies in 15 women with nutritional osteomalacia and proximal muscle weakness showed brief duration motor unit action potentials of normal amplitude and increased proportion of polyphasic motor unit potentials in the majority of them. By employing quantitative methods of electromyography, more positive results were obtained, thus reducing the sampling data. The histology showed non-specific muscle fibre atrophy without degenerative changes and the clinical and electromyographic examinations together showed clear evidence of a myopathy, suggesting a reversible transient block of the muscle fibres. Contrary to a recent suggestion, the nature of muscular change in osteomalacia remains the same regardless of its cause being nutritional or otherwise.

Vitamin D supplementation does not improve human skeletal muscle contractile properties in insufficient young males

“…case studies have previously described a proximal muscle weakness associated with nutritional osteomalacia that is responsive to supplementation with vitamin D (Ziambaras and Dagogo-Jack 1997;Irani 1976;Smith and Stern 1967;Al-Said et al 2009). recently, in contrast to our current findings, we have observed an improvement in 10-m sprint times and vertical jump height following supplementation in a group of vitamin D deficient young athletes (close et al 2013b).…”

“…genome-wide analyses suggest that any improvement in vitamin D status significantly affects the expression of a large number of genes that have many biological functions (Hossein-nezhad et al 2013). Specifically regarding skeletal muscle, it has long been understood that patients with osteomalacia resultant from inadequate dietary vitamin D intake often display an accompanying skeletal muscle myopathy presenting as a proximal muscle weakness that is responsive to vitamin D supplementation (Ziambaras and Dagogo-Jack 1997;Irani 1976;Smith and Stern 1967;Al-Said et al 2009). Emerging data now suggest at a cellular level that skeletal muscle is indeed a tissue that responds functionally to vitamin D. recent data have demonstrated in vivo improvements in mitochondrial oxidative function when severe vitamin D deficiency is corrected in humans (Sinha et al 2013).…”

Vitamin D deficiency is endemic in Middle Eastern sportsmen

“…In the mid-20th century athletes were supposedly using UV light as a performance aid, although scientific evidence to support its use was limited (29)(30)(31) . Severe 25(OH)D deficiency is known to be associated with reduced type II muscle fibre composition (44)(45)(46)(47) and the sarcopenia associated with ageing is thought to be affected by 25(OH)D concentrations (48)(49)(50) . Recently, 25(OH)D deficiency was shown to be associated with reduced physical performance both in young and aged populations (32,44) .…”

The relationship between vitamin D status and muscle strength in young healthy adults from sunny climate countries currently living in the northeast of Scotland

“…Furthermore, no longitudinal data studying the relationship between vitamin D and muscle strength and how this relationship is affected by emigrating from low to high latitudes exists. Early evidence supporting a role of vitamin D in muscle health can be found in patients with rickets and osteomalacia, who develop myopathy and muscle weakness which is reversible with vitamin D supplementation [2][3]. Further support for a role of vitamin D in muscle came from the identification of vitamin D receptors in skeletal muscle tissue, although this remains controversial [4][5][6].…”