Handgrip strength might possibly be improved by oral vitamin d₃ supplementation in older people with sarcopenia: A systematic review and meta-analysis

Background/Purpose: Supplementation with vitamin D₃ has been reported to increase appendicular muscle strength. This meta-analysis reports the effects of oral vitamin D₃ supplementation on sarcopenia. Methods: We conducted a systemic search of the electronic databases: PubMed, Cochrane Library and CINAHL from January 2008 to July 2020. We included clinical trials on humans. The outcome was change in handgrip strength. Results: A total of 269 studies were identified. Eight studies were included. The cumulative sample size was 1,334 patients. The majority were elderly (mean 65.2 years) and women (63.6%). The intervention period ranged from 3 to 12 months with daily doses from 100 IU to 20,000 IU per week. The total mean difference in handgrip strength change was 0.60 kg (95% confidence interval (CI):-0.78 to 1.98). In studies with daily vitamin D₃ dosage over 800 IU, there was a trend of association between handgrip strength and vitamin D₃ with a total mean difference of 0.62 kg (95% CI: 0.07 to 1.17). Conclusion: Oral vitamin D₃ supplementation may not be effective in increasing handgrip strength among older adults. However, there was a tendency of increased handgrip strength in studies with a daily dosage of vitamin D₃ over 800 IU. Dosage may play a crucial role.