Oral Virtual Presentation (Virtual only) ESA-SRB-ANZBMS 2021

Vitamin D supplementation and exercise for improving physical function, body composition and metabolic health in overweight or obese older adults with vitamin D deficiency: a randomised, double-blind, placebo-controlled trial (#16)

Jakub Mesinovic 1 2 , Alexander Rodriguez 1 3 , Mavil May Cervo 1 , Anoohya Gandham 1 , Cecilia Xu 1 , Costas Glavas 1 2 , Barbora De Courten 1 , Ayse Zengin 1 , Peter Ebeling 1 , David Scott 1 2
  1. Department of Medicine, Monash University, Melbourne, Victoria, Australia
  2. Institute for Physical Activity and Nutrition (IPAN), Deakin University, Melbourne, Victoria, Australia
  3. School of Medical and Health Sciences, Edith Cowan University, Perth, Western Australia

Background: Vitamin D supplementation may have non-skeletal health benefits and enhance exercise responsiveness, particularly in those with low vitamin D concentrations. We investigated whether vitamin D supplementation taken prior to, or during, a 12-week exercise program improves metabolic health, body composition or physical function in overweight and obese older adults with vitamin D deficiency.

Methods: Fifty overweight and obese older adults (mean±SD age: 60±6 years; BMI 30.6±5.7) with vitamin D deficiency (25-hydroxyvitamin D [25(OH)D] <50nmol/L) were recruited. Participants were randomly allocated to receive either vitamin D3 (4000 IU/day) or matching placebo for six months. Between months 3-6, all participants completed a 12-week multi-modal exercise program (aerobic and resistance exercise) at a frequency of three days per week (one supervised and two home-based sessions) while continuing with vitamin D/placebo. Mean changes in biochemical parameters, body composition and physical function at three and six months were compared between groups.

Results: At three months, vitamin D supplementation increased 25(OH)D levels (placebo = 2.5±14.7nmol/L; treatment = 43.4±18.4nmol/L; P<0.001) and reduced stair climb times (placebo = 0.3±1.0sec; treatment = -0.2±1.0sec; P=0.046). At six months, vitamin D supplementation combined with multi-modal exercise reduced waist circumference (placebo = 1.3±7.3cm; treatment = -3.0±6.1cm; P=0.022) and decreased waist-to-hip ratio (placebo = 0.01 ± 0.05; treatment = -0.03 ± 0.05; P=0.005). Vitamin D supplementation had no effect on gait speed (primary outcome) or any other biochemical, body composition or physical function parameters when taken alone, or in combination with exercise.

Conclusion: Vitamin D supplementation increased 25(OH)D levels and augmented waist circumference losses following a multi-modal exercise program in overweight and obese older adults with vitamin D deficiency. Vitamin D supplementation alone also reduced stair climb times. Future studies should focus on individuals with moderate or severe vitamin D deficiency, as these individuals might experience greater therapeutic benefits.