Researchers studied the blood levels of vitamin D of about 100 college athletes. They also tested how fast the athletes could sprint, how high and how far they could jump, and how much weight they could squat for one rep.
About 1 in 3 of the athletes had inadequate levels of vitamin D (less than 72 nanomoles per litre of blood).
Those athletes’ one-rep maxes on the squat were 77 per cent lighter than people with higher D levels.
In addition, their shuttle runs were 18 per cent slower, their vertical leaps 15 per cent lower, and their distance jumps 80 per cent shorter.
Why? One theory is that vitamin D may help your muscle cells release calcium more efficiently during the muscle contraction process, says study author Dr Rachel Hildebrand.
That can lead to faster and more powerful contractions, says Hildebrand - meaning you can jump higher, sprint faster, and lift heavier.
Dr Brad Schoenfeld, an assistant professor of exercise science at Lehman College, is skeptical that vitamin D could affect your strength that much. The study was small, and it only found a link between D and strength - it doesn’t necessarily prove cause and effect.
Still, there is evidence that D plays a role in muscle strength and development, he says.
Regardless, it would be wise for many of us to get more of the vitamin. One 2010 study found that 42 percent of adults were deficient.
The Endocrine Society recommends consuming 1,500 to 2,000 IU of vitamin D a day. Load up on D-rich foods like fatty fish and fortified milk, which contains about 100 IU per cup, to increase your intake.
This article was originally published on MensHealth.com