​The importance of Zinc אבץ
A  good 30 years ago already, a booklet about anorexia was published where the writer[forgot his name] claimed to have treated this condition with zinc supplements successfully.
Children who don’t like all kinds of foods may have a zinc deficiency because of a lack of smell.
If you can eat plenty of nuts [especially almonds] and you will cover you zinc needs.
A lack of zinc can also reduce the immune system.
Many children in Israel are lacking zinc in my estimation.
See now below the summary of Mateljan

Can a deficiency in zinc affect sensory organs?

Acute depletion of zinc can causes loss of the sense of taste and appetite. The level of zinc deficiency necessary to cause these changes appears to be more severe than the immune system changes reported in the article on zinc and is often related to another factor, such as cancer treatment or anorexia. One research group recently estimated that about 15% of elderly people who lost their sense of taste did so due to zinc deficiency, and some others did so due to more serious conditions, so make sure to report this symptom to your doctor if you develop it.

Like the other symptoms related to zinc deficiency, this change in the sense of taste appears to be reversible in the majority of people who get back to normal zinc status. Here are a couple of recipes—Braised Red Curry Lamb and Vegetables as well as healthy Chef’s Salad with Walnuts and French Dressing—that should help to combat zinc-related loss of sense of taste, both by acting as good sources of zinc, and by including a good zing of spices.

Zinc is also critical to vision. It works together with vitamin A to help sense light and to send nerve impulses to the brain. Although we don’t currently know how much of age-related vision loss is due to zinc deficiency, researchers have shown that zinc levels in the retina (the part of the eye that sees the light) decline in tandem with vision loss.