Dear Doctor: My daughter is two years and eight months and she enjoys eating raw Irish potatoes. Why would one chew on raw Irish potatoes and swallow them as such? Could there be a deficiency?
— Phenomena Friday, Ibanda

Dear Friday: Usually when humans eat substances with no nutritious value such as soil, it is thought that they may have a deficiency or they have a mind ailment (obsessive compulsive disorder). Irish potatoes when eaten raw, may be unappealing due to their mildly bitter taste. Though raw Irish potatoes are not toxic, their starch is indigestible and may not have nutritional value.
The uncooked and indigestible starch will then reach the large intestines where intestinal fermentation bacteria will act on it leading to a gassy, bloated and cramping abdomen. Although none of these effects is a threat to health, they are uncomfortable and inconvenient.
That said some types of Irish potatoes produce two natural substances (alkaloids), solanine and chaconine, that may lead to diarrhoea, nausea, cramping, headaches and in extreme cases organ failure and death when consumed. Therefore, you should keep all raw Irish potatoes out of her reach. Consider taking the child to a doctor to assess whether your daughter has a compulsive disorder, hidden stress among some other health issues.
That said, eating raw food puts her at risk of foodborne illness while cooking, peeling or washing the potatoes may eliminate most food borne germs and worms.
At that age, a child wants to explore the world including eating unusual things. Since toddlers lack many of the skills required for safe eating, they should be protected by putting all inedible or dangerous substances out of their reach.