Men wishing to acquire a higher sex drive can benefit by exposing their body to the sun's rays, as a study by Austrian scientists has found sunshine increases level of male sex hormone testosterone.

According to the study at the Medical University of Graz, Austria, men with high blood vitamin D levels have significantly higher testosterone levels than men with less vitamin D, the Daily Express reported.

Ninety percent of the body's vitamin D is produced by the action of sunlight on the skin, say researchers, adding that sufficiently high levels of the vitamin have a "positive influence" on testosterone.

Ad Brand, of the Sunlight Research Forum, in Holland, said: "Men who ensure that their body is at least sufficiently supplied with vitamin D are doing good for their testosterone levels and their libido."