Conception, pregnancy and breastfeeding
Zinc is regarded as a 'trace' mineral, however nearly all our body cells contain some zinc, with the highest concentrations in our muscles and bones. Zinc does not readily move into the blood stream from the muscles and bones when blood levels are low (like calcium), therefore zinc needs to be included in our daily diets.
Zinc plays an important role in protein synthesis, growth, insulin regulation, blood clotting, vitamin A usage and learning performance. It is essential for our taste sensation, vision, reproduction and wound healing and contributes to a strong immune system, strengthening the cell's resistance to 'free radicals'. A zinc deficiency can impair all these functions.
Zinc deficiencies were first realised in the middle-east in the 1960's. Children and adolescents (who require more zinc because they are growing rapidly) were experiencing poor growth, slow sexual maturity, diarrhoea and anorexia (leading to overall malnutrition), frequent infections, poor wound healing and learning difficulties. This was because their diets were low in zinc-rich foods (such as meats) and high in unleavened breads, legumes and whole grains, which contain phytates (the husks of grains and seeds). Phytates bind with zinc and reduce its absorption from the intestine.
Zinc is released with digestive juices when we eat, of which some is reabsorbed with the digested food. The rest of the zinc passes out through our bowel motions. Small amounts of zinc are also lost through sweating, menstrual fluids and semen. Blood tests for zinc are generally unreliable because most zinc is found in our cells, rather than in our blood.
Recommended Daily Intake (RDI)for zinc is about 10-12mg per day. This can generally be obtained through a well-balanced diet. However, children, pregnant women and the elderly may be prone to not obtaining adequate zinc through their diet.