Vitamin D and muscle strength throughout the life course: a review of epidemiological and intervention studies

Abstract

The putative role of vitamin D in muscle function and strength throughout the life course is of interest because muscle strength is required for engagement in physical activity at all ages. As vitamin D deficiency is widely reported in the population, especially in countries at high latitude, the potential importance of vitamin D in muscle function throughout life, and the potential impacts on growth and development, participation in physical activity, and effects on skeletal and cardio-metabolic health, comprise an important topic for discussion. This review provides an overview of muscle function and summarises the role of the vitamin D receptor and the proposed molecular mechanisms of action of vitamin D in muscle cells. In addition, the review provides a comprehensive assessment of the clinical evidence surrounding the association between vitamin D and muscle strength. Among adults, particularly older adults, cross-sectional and cohort studies reported a positive association between vitamin D status and muscle strength. These associations have been largely confirmed by intervention studies. Limited research has been carried out in adolescents and children; two cross-sectional studies in adolescents have suggested an association between serum 25-hydroxyvitamin D concentrations and muscle strength. However, the two intervention studies in adolescents have yielded conflicting results. Other than a single observational study, data in young children are very limited and further investigation in under 12-year-olds is warranted.

The pathogenetic bases of sarcopenia

“…Further clinical studies are needed in order to confirm this preliminary results. During aging, it has been registered a decline in 25(OH)vitamin D3 serum levels associated with reduced muscle mass, strength and performance in older adults (46,47). Moreover, a recent skeletal muscle gene expression study carried out in older adults (68-79 years) showed that lower expression of vitamin D receptor (VDR) was associated with higher lean mass (48).…”

Vitamin D Status, Muscle Strength and Physical Performance Decline in Very Old Adults: A Prospective Study

“…Supplementation with calcifediol (20 µg over 6 months) improved appendicular lean mass, physical performance (Short Physical Performance Battery), 4-m gait speed, and reduced mean number of falls in post-menopausal women (aged 68 years) who were diagnosed with osteoporosis or had 25(OH)D concentration <75 nmol/L [18]. Lastly, results from observational studies [3,19], although inconsistent, have suggested that a 25(OH)D concentration of <50 nmol/L exerts a negative effect on various measures of muscle strength and function and physical performance in older adults aged ≥60.…”

Vitamin D and calcium supplementation, skeletal muscle strength and serum testosterone in young healthy adult males: Randomized control trial

“…The importance of calcium in muscle contraction and the ease with which myopathy in osteomalacia is reversed with vitamin D therapy indicates possible role of vitamin D on skeletal muscle strength. Most of the randomized control trials (RCTs) have been in elderly subjects and showed variable effects of vitamin D supplementation on muscle strength . Factors which might explain this variability are (i) wide age range, 50 years to centenarians, (ii) differences in baseline serum 25(OH)D, sufficient to deficient, (iii) absence of calcium supplementation (iv) lack of stratified analysis accounting interindividual differences in sex hormone and (v) presence of sarcopenia.…”