Zinc is involved in the biochemical processes supporting life, such as cell
ular respiration, DNA reproduction, maintenance of cell membrane integrity
and free radical scavenging. Zinc is required for the activity of more than
300 enzymes, covering all 6 classes of enzyme activity.
Zinc binding sites in proteins are often of distorted tetrahedral or trigon
al bipyramidal geometry, made up of the sulphur of cysteine, the nitrogen o
f histidine or the oxygen of aspartate and glutamate, or a combination. Zin
c in proteins can either participate directly in chemical catalysis or be i
mportant fur maintaining protein structure and stability.
The nutritional habits of elite athletes during training and competition ar
e quite different from the recommended diet in the majority of the populati
on. Endurance athletes often adopt an unusual diet in an attempt to enhance
performance: an excessive increase in carbohydrates and low intake of prot
eins and fat may lead to suboptimal zinc intake in 90% of athletes. Mild zi
nc deficiency is difficult to detect because of the lack, of definitive ind
icators of zinc status. In athletes, zinc deficiency can lead to anorexia,
significant loss in bodyweight, latent fatigue with decreased endurance and
a risk of osteoporosis.