Vitamin D may be just what the doctor ordered when it comes to increasing sperm mobility.

According to a study done by researchers at Copenhagen University Hospital, Vitamin D can help improve the forward mobility of sperm as well as increase the percentage of mobile sperm.

Researchers caution, however, that men with fertility disorders shouldn’t start taking large doses of Vitamin D.

"Our study is not sufficient and should not be used to change existing treatment practices," said Martin Blomberg Jensen of Copenhagen University Hospital.

"This finding is not sufficient in determining whether vitamin D supplements may improve sperm quality in normal or infertile males."

The study used a sample of 300 normal males and provided them Vitamin D supplements. Not only did the percentage mobile sperm improve, but in lab tests Vitamin D improved the forward mobility of human sperm.

Vitamin D has been proven to have a positive effect on sperm production and movement in animals, but the new study confirms such news for human males as well.

With no known medical treatments to improve serum quality, the research does provide some new directions.

"It uncovers some of the functions of vitamin D and generates new hypotheses," said Jensen, who also led the study.

"This is an intriguing finding, because it suggests that vitamin D has an effect on sperm movement and function."

On the Web: Human Reproduction, March 22.