Vitamin D Makes You More Physically Fit
New research suggests that supplementing with Vitamin D may make you more fit than exercise alone can accomplish. What was discovered was that taking a daily supplement of vitamin D for two weeks significantly improved benchmarks of fitness, while also reducing blood pressure and cortisol (stress hormone) levels.
This study, done at the Queen Margaret University in Edinburgh, subjected 13 healthy men and women to basic medical tests, and then had them work out on an exercise bike. Some were then given a daily vitamin D supplement (only 2,000IU), and others were given a placebo: two weeks later they were brought back to the exercise bike.
While those who received the placebo were shown to be no fitter than they had been at the beginning of the study, those who had taken the vitamin D pills did much better on the bike than they had done at the beginning of the study. They were able to cycle one third further than they had at the beginning of the study, and found the peddling work easier to do this time round.
Ultimately the scientists could not say why the vitamin D would improve exercise performance, and went on to suggest that a larger study would be needed to confirm this observed benefit of vitamin D.
But, this next study may answer the question raised above: why would vitamin D improve exercise performance?
Vitamin D Increases Muscle Strength
For some time now science has linked vitamin D deficiency with muscle weakness, especially in the elderly. When we age we lose muscle mass and strength, even if we are relatively healthy. This loss of muscle strength leads to a reduction in functionality, and an increased risk of falling and fractures. Aside from fatigue, another indication of muscle weakness that is a result of vitamin D deficiency is a feeling of heaviness in the legs.
Some older studies have indicated that metabolites of vitamin D affect muscle cell metabolism and muscle fiber composition. Last year, researchers from the University of London did a meta-analysis of seven such published studies that examined the relationship between vitamin D and muscle strength.
Subjects were healthy people of both genders, ranging from 21 to 31 years old, and the studies covered testing periods running from 4 weeks to 6 months, with dosages of vitamin D ranging from 4,000IU daily to 60,000IU per week. The conclusion of the meta-analysis was that “vitamin D supplementation significantly increased upper and lower limb strength.”
(J Sci Med Sport. 2015 Sep;18(5):575-80; Epub 2014 Aug 11. “Effects of vitamin D supplementation on upper and lower body muscle strength levels in healthy individuals. A systematic review with meta-analysis.” Tomlinson PB, et al.)