Vitamin D level and its relation to muscle and fat mass in adult male Arabs

Low levels of vitamin D have been linked with increased adiposity and diminished muscle strength. Whether it is also related to fat deposition in muscle tissues is not studied well. This study explored the associations between circulating 25-hydroxyvitamin D (25(OH)D) and fat deposition in muscle tissues of adult Arab males. A total 465 adult Saudi males were included in this cross-sectional study. Anthropometrics, body composition and muscle strength were assessed. Serum 25(OH)D was determined and quantified enzymatically. They were grouped according to vitamin D status: deficient (25(OH)D < 50 nmol/l) N = 325 (69.9%) and sufficient (25(OH)D > 50 nmol/l)140 (30.1%). Mean level of lean/height(2), lean-arm-legs and lean-arms-legs/height(2) were significantly higher in 25(OH)D deficient participants (p-values 0.03; 0.05 and 0.01 respectively). Thigh strength was significantly higher in 25(OH)D sufficient participants than their deficient counterparts (p = 0.02). In all participants, a significant correlation between 25(OH)D was observed with age and thigh-strength (p-values < 0.05), while a significant inverse correlation between 25(OH)D and lean/height(2), lean-arms-legs, lean-arms-legs/height(2), fat (%) region, fat arms, fat legs, fat trunk, lean legs were noted. In conclusion, low circulating 25(OH)D is associated with enhanced fat infiltration in muscle tissues of adult Arab males.