A recent randomized controlled trial led by Andres E. Carrillo from Purdue University has found that vitamin D supplementation may help peak power in the short term, but perhaps not in the long run over the course of a workout program.
The researchers split 23 participants into two groups, ten in the vitamin D group (5 females, 5 males) and thirteen in the placebo group (7 females, 6 males). The mean age was 26 years old, with participants weighing a mean of 191 pounds in the vitamin D group and 202 pounds in the placebo group. The percentage body fat in both groups was a little over 40 percent, categorizing the participants as obese. The vitamin D group received 4,000 IU/day, while the control group received a placebo.