Ngesikhathi sokuwa, izinsuku zifushane kakhulu uma ziqhathaniswa nehlobo. Iningi labantu lizijwayeza ngaphandle kobunzima iqiniso lokuthi kuba mnyama ngaphambi kuka-6 ntambama, kepha abanye, abavame ukuzwela kakhulu, bayahlupheka ukukhathazeka nokudangala ngenxa yokwehla kwamahora okukhanya kwelanga.
Lokhu kungenxa yesifo esaziwa nge-SAD. (ukuphazamiseka kokuphazamiseka kwesizini). Izinkathi zonyaka ziyashintsha, futhi nazo ukukhanya kwelanga, okuthinta isigqi se-circadian, iwashi langaphakathi lomzimba womuntu elibamba iqhaza ekukhiqizeni ama-hormone, kanye nasemagagasi obuchopho. Lokhu kudala ukuthi abantu abazwela kakhulu babone ushintsho esimweni sabo sengqondo ngoba uhlelo oluphakathi lwezinzwa lwenza impendulo ethukuthele efana naleyo ekhiqizwa yi-jet lag.
Ukusinda ezinsukwini ezimfushane nezimfushane, lapho sishiya khona umsebenzi futhi sekuvele kumnyama bhuqe, kulula uma sibona ukuthi ekupheleni kukaDisemba, izinsuku zizoqala ukwelula futhi. Ukwenza umqondo kuyasiza, kepha kwesinye isikhathi akwenele, futhi kulezo zimo singazama hlela kabusha ishejuli ukuze uthole ukukhanya kwelanga ngangokunokwenzeka noma usebenzise ukwelashwa okukhanyayo okumhlophe okukhanyayo.
Izithako ze-Vitamin D ngelinye ikhambi le-SAD ngoba izifo eziningi, ikakhulukazi ukudangala, zihambisana nokushoda kwalesi sakhi. Unganqikazi ukubonisana nodokotela wakho ngalolu daba, ikakhulukazi uma uhlangabezane nemizwa ephansi ngokungena kwekwindla. Kodwa-ke, ungazama futhi izinsuku ezimbalwa uwedwa ukubona ukuthi umzimba wakho uphendula kahle yini ku- ukudla okwengeziwe kwe-vitamin D ekudleni, njengowoyela wesibindi se-cod, i-salmon, i-tuna, ubisi, i-yogurt, amaqanda nokusanhlamvu okuqiniswe ngovithamini D.