The association between vitamin D and muscle health in male and female adults aged 40 and older in Newfoundland and Labrador

Morgan LeDrew
MSc Student 
Department of Biochemistry

Date: March 10, 2025
Time: 1:00 p.m. to 2:00 p.m. 
Room: CSF 1302

Abstract:

Background: Recent evidence suggests that vitamin D status may impact muscle health. Maintaining muscle health is essential for independence, mobility, and quality of life. Understanding this relationship is crucial for supporting healthy aging.

Objectives: To determine the association between vitamin D status and muscle health in adults aged 40+ in Newfoundland and Labrador.

Methods: Male and female adults aged 40+ (n = 49) were assessed for fat and muscle mass (kg, %) using bioelectrical impedance analysis (TANITA MC-780U Plus P). Muscle strength was measured using the JAMAR Hydraulic Hand Dynamometer. Muscle function was assessed using the Short Physical Performance Battery. A 3-day diet diary using the ASA24 tool, along with a sun exposure and Global Physical Activity Questionnaire were completed. Group comparisons were conducted using independent sample t-tests or Mann-Whitney U, as appropriate. Correlations were assessed using Spearman.

Results: Participants were 57.5 ± 8.7 years (mean ± SD) of age, 76% were female (F), 76% were born in NL, and 96% were white. Muscle mass 46.1 ± 4.6 kg F vs 63.0 ± 7.7 kg M. Fat mass was 22.8 ± 7.2 kg F vs 22.9 ± 8.4 kg M. Grip strength was 23.7 ± 4.1 kg F vs 42.8 ± 10.9 kg M. Higher muscle mass (%) was correlated with better gait speed (r = 0.398, p = 0.005) and more time spent doing physical activity (r = 0.507, p < 0.001). Muscle mass (kg) was correlated with higher IGF-1 concentration (r = 0.316, p = 0.036). Furthermore, dietary vitamin D intake inversely correlated with measures of adiposity, including fat mass (r = -0.418, p = 0.017) and BMI (r = -0.394, p = 0.023), as well as positively correlated with muscle mass (%) (r = 0.345, p = 0.053). In addition to dietary intake, vitamin D supplement intake inversely correlated with fat mass (kg, %) (p = 0.03, r = -0.320). Our findings showed that individuals with higher muscle mass (%) had better muscle function, including higher gait speed, higher physical activity levels, and better dietary habits.