The review included data from 310 adults with an average age of between 21.5 and 31.5 years.
The seven trials, which included 67% females, lasted from four weeks to six months while dosages ranged from 4000 international units (IU) per day to 60,000 IU per week.
“This review has found that vitamin D3 supplementation improves upper and lower limb muscle strength in a healthy, adult, athletic and non-athletic population between the ages of 18 and 40,” the authors wrote in the Journal of Science and Medicine in Sport.
The two studies that reported the most significant results employed total dosages between 60,000 and 14,000 IU vitamin D per week for six to four months.
They said further research was now needed on its effect on muscle power, endurance and maximum strength.
Previous research on vitamin D has focused on vitamin D supplementation and muscle strength in frail, deficient and elderly women. This latest review – compiled by researchers at Queen Mary University of London – was the first systematic summary of the impact on muscle strength in young, healthy individuals.
Source: Journal of Science and Medicine in Sport
Vol 18, Iss 5, pp 575–580, doi:10.1016/j.jsams.2014.07.022
“Effects of vitamin D supplementation on upper and lower body muscle strength levels in healthy individuals. A systematic review with meta-analysis”
Authors: P. B. Tomlinson, C. Joseph and M. Angioi