According to the site:
"One of the first signs of zinc deficiency can be disrupted sleep patterns...Those with low zinc tend to eat more frequently. They may have poor concentration, poor short term memory recall, mental apathy, eczema, dermatitis, hay fever, allergies, asthma, frequent colds, sore throats, ear infections, thrush, warts. They may be fussy eaters, lose sense of taste and smell, have pre-dinner tantrums, temper outbursts, anorexia or bulimia, acne, teenage depression, be hyperactive or moody. "Zinc is critical for fighting infections--and, according to the site "Zinc is secreted into body fluids as an antiseptic" and "Body zinc is depleted by high carbohydrate diets." and "Calcium supplements and high calcium foods reduce zinc absorption by half. Stress (physical, emotional or chemical) as well as pollutions, pesticides and toxic metals leave us short on zinc. "
My son tested low in zinc according to recent blood tests and has many signs of a zinc deficiency. Anecdotally, last night he was screaming in his sleep. After 15 minutes of listening to him and trying to comfort him, I remembered I had forgotten to give him the zinc, so I gave him some in a little water and he immediately stopped crying and fell asleep. It is not science--perhaps it was the water-- but when I looked it up I noticed that a disrupted sleep pattern was associated with low zinc. Most people, including my son, don't usually have such dramatic responses to zinc supplementation. More typical signs of zinc deficiency are: poor growth, picky eating, and slow wound healing.