Aha bavuga ko bitewe n’agace umuntu abarizwamo, aho atuye cyangwa ingere muri rusange yaba amaramo igihe kinini,  bishoboka ko amafunguro akunze kurya ashobora kugira uruhare mu gufata neza uruhu rwe mu buryo bugaragara.

Aya makuru agaruka cyane ku mikorere y’izuba ku ruhu, aho bavuga ko ryonona cyane utunyabuzima fatizo tugize agace k’inyuma k’uruhu, kanazwiho kuba ari ko gashinzwemo ubwoya, aho avuga ko akenshi usanga ryibasira cyane utunyabuzima fatizo tugize uruhu (cellules epidermiques).

Hifashishijwe amafunguro hakiyongeraho n’uburyo umubiri ushobora kuyakira neza, bishoboka ko uruhu rwarushaho gutohagira nta bindi bikoreshejwe, byaba ibyongerwa ku ruhu cyangwa ibindu umuntu yanywa nk’imiti.

Aha bavuga ko nk’uko umubiri ushobora kugaragaza ko urwaye indwara zikomoka ku mirire mibi, ari nako uruhu rushobora kugaraga neza umuntu aramutse ahawe amafunguro akwiye.

Mu gihe uyu muntu atayabona, usanga binoroha cyane ko uruhu rurwaragurika cyane ko unasanga uko ruri hanze, ari nako binoroshye guhura na za mikorobe ziboneka mu gace atuyemo.

Aha bagaruka ku mafunguro akungahaye kuri za vitamine, bagatanga urugero kuri vitamine A  akenshi ikomoka ku bihingwa bifite ibara ritukura, aho bavuga ko igira uruhare mu gusana cyane aho izuba rikunze kwangiza.

Usanga umubiri ubona iyi vitamine A utarangwa no gukanyarara cyane, ikindi ngo usanga iyi vitamine iyo ifatanyije n’izindi, birwanya indwara yose ishobora kwegera umuntu