According to a new study, men who have a taurine deficiency are more likely to become infertile.
Japanese scientists found mice lacking the amino acid were more likely to be sterile - and their sperm had deformed tails.
However, scientists found that when the rodents were given taurine, found in meat, vegetables and pulses, the tails of their sperm reverted to normal.
According to researchers, people with anxiety, gout, obesity or kidney failure are known to have lower levels.
Vegans and vegetarians are scientifically understood to be at a higher risk of taurine deficiency because meat is a key source.
However, the human body can make its own supply of the amino acid with enough nutrition from vegetables, nuts and pulses and can also be found in breast milk and in energy drinks such as Red Bull.
The study, conducted at the University of Tsukuba and Cornell University in New York studied mice's sperm to make the conclusion.
Researchers led by Dr Atsushi Asano claim taurine helps them to keep their structure once outside of the testicle.
The team discovered sperm absorb taurine from the genital tract, rather than making it themselves, so their supply depends on diet.
Speaking about the study, Dr Asano said that the findings show the production of taurine in the male reproductive tract, and its absorption by sperm, are pivotal mechanisms for male fertility.
The research was published in the Federation of European Biochemical Societies' Journal.
The study comes amidst widespread concern that the sperm count among men are falling rapidly around the world....