Higher Levels of Vitamin D Associated with Higher Exercise Capacity
Vitamin D is naturally present in a few foods, added to others, and available as a dietary supplement. It is produced when ultraviolet rays from sunlight strike the skin. Vitamin D helps to absorb calcium from the intestine, improves muscle function, improves the immune system (which protects against infection), and reduces inflammation.
Kaul and colleagues from University Medical Greifswald in Germany published the results of two studies which evaluated levels of Vitamin D in the blood and exercise capacity in different groups of healthy individuals. The findings were published online in the December 2015 issue of the British Journal of Nutrition.
There were 1,377 participants in the first study. The second study was done to confirm findings of the first study and included 750 participants. In both studies blood was drawn to measure 25-hydroxyvitamin D (the best indicator of Vitamin D status) and all subjects performed exercise on a stationary cycle (ergometer) until exhaustion.
Findings: Subjects with higher levels of Vitamin D showed a higher exercise capacity compared with subjects who had low blood levels. These findings were statistically significant. The results were true regardless of age, sex, and season.
My Comment: These findings raise the consideration of taking a vitamin D supplement, especially if you live somewhere like New Hampshire (as I do) where being outdoors and being exposed to sunshine is minimal during the winter months. Vitamin D can also decrease blood pressure and reduce the risk of heart disease and type 2 diabetes. Remember that this study was done in healthy individuals, so you can not assume that the same results would be found in those with COPD.
Of course, you can discuss whether taking vitamin D is beneficial with your health care provider. Note, The NIH emphasizes that people over age 50 generally need higher amounts of vitamin D than younger people do.