Results from a new study show that vitamin D2 may not be beneficial to muscle health in athletes.
There is ongoing study about the difference in effects of vitamin D3 versus vitamin D2 on human health. Vitamin D3 is the form of vitamin D that humans produce from sun exposure. Vitamin D2 is a form of vitamin D produced by certain plant species, like mushrooms. Supplement manufacturers make both kinds, but vitamin D3 is more commonly produced and found on store shelves.
In recent years, researchers have found that vitamin D3 may be more beneficial of the two and have questioned the use of vitamin D2.
Recently, researchers at the Appalachian State University in North Carolina set out to see the effects of vitamin D2 supplementation on reducing exercise-induced inflammation and muscle damage in athletes.
The research team recruited NASCAR pit crew members for the study. Pit crew members often undergo intense weight lifting and other muscle related exercise during their job.
They conducted a double blind randomized controlled trial study on pit crew members for six weeks. During the six weeks, the pit crew members either took 3,800 IU/day of vitamin D2 or a placebo.
They found that the pit crew members taking vitamin D2 had increased muscle damage compared to those taking a placebo.
“This is the first time research has shown that vitamin D2 supplementation is associated with higher muscle damage after intense weight lifting, and thus cannot be recommend for athletes,” said lead researcher Dr. David Nieman.
Based on their results, Dr. Nieman suggests that something is occurring at the muscle level with vitamin D2 that specifically worsens muscle damage.
“High vitamin D2 levels are not a normal experience for the human body,” Dr. David Nieman stated. “Taking high doses of vitamin D2 caused something to happen at the muscle that isn’t in the best interest of the athletes.”
During the study, those who took vitamin D2 had their vitamin D3 levels decrease, which is one theory for why vitamin D2 increased muscle damage.
More studies looking at the comparison of vitamin D2 and vitamin D3 in muscle health are needed for more conclusive answers.
Research shows taking vitamin D2 is a poor choice for athletes. Appalachian State University News, 2014.