Vitamin d and calcium supplementation improves physical function in the severely obese: a controlled clinical trial

Physical dysfunction is common in the severely obese (BMI>40 kg/m2) and may contribute to their higher than normal mortality. Vitamin D supplementation improves physical function in the elderly. We hypothesised that vitamin D supplementation improves physical function in severely obese people. In a cohort of severely obese people attending our unit we measured the time taken to walk 500 m on two occasions separated by 12 weeks. After the initial assessment those with a serum 25‐ hydroxyvitamin D (25OHD) less than 50 nmol/L who were suitable and willing received oral vitamin D (800 IU/day) and calcium (1,200 mg/day) supplementation. The remaining participants received no supplementation. (Table presented) The median age of the participants was 46.9 years and their median BMI was 52.1 kg/m2. The change in the 500 m walk time correlated with the change in the physical performance score (r= ‐0.34, p = 0.028). Vitamin D supplementation decreased the 500 m walk time in this cohort of severely obese people with vitamin D deficiency. In the severely obese a vitamin D dose higher than the recommended daily allowance is required to bring the 25OHD above 50 nmol/L and may effect greater improvement in physical function.