Tun farkon shekarun 1930, masana kimiyya sun gano cewa fallasa hasken rana ko amfani da man zaitun, man flaxseed, da sauran abinci masu ba?ar fata na UV na iya magance osteoporosis. Karin bincike da masana kimiyya suka yi sun gano kuma sun sanyawa bitamin D suna a matsayin sinadari mai aiki a jikin dan adam don yakar kashi kashi.

Vitamin D (VD a takaice) bitamin ne mai narkewa, wanda rukuni ne na abubuwan da aka samo asali na steroid tare da tasirin rigakafin rickets da makamantansu. Mafi mahimmanci sune bitamin D3 (cholecalciferol, cholecalciferol) da bitamin D2 (calciferol). Vitamin D a cikin abincin yana fitowa ne daga abinci na dabba kamar hanta kifi, gwaiduwa kwai, man shanu da sauransu. Bayan an sha, ana tsotse shi daga ?ananan hanji a gaban bile kuma a kai shi cikin jini ta hanyar sigar chylomicrons. An canza shi zuwa 1,25-dihydroxyvitamin D3 ta hanta, koda, da kuma mitochondrial hydroxylase, wanda ke da aikin nazarin halittu kuma yana iya tada kira na furotin daurin calcium (CaBP) a cikin mucosa na hanji, inganta ?wayar calcium, da inganta ?asusuwa. 7-dehydrocholesterol, wanda ake samu na cholesterol a cikin jikin mutum, ana adana shi ta hanyar subcutaneously kuma ana iya canza shi zuwa cholecalciferol a ?ar?ashin hasken rana ko hasken ultraviolet. Yana da sinadarin bitamin D wanda ke inganta shayar da calcium da phosphorus.

VD asali ne na steroids. Yana da wani farin crystal, mai narkewa a cikin mai, tare da barga kaddarorin, high zafin jiki juriya, antioxidant, ba resistant zuwa acid da alkali, kuma za a iya halakar da fatty acid lalata. Hanta dabba, man hantar kifi, da gwaiduwa kwai suna da wadatar abun ciki. Bukatar yau da kullun ga jarirai, yara, matasa, mata masu juna biyu, da masu shayarwa shine 400 IU (raka'a na duniya). Lokacin da aka rasa, manya suna fuskantar osteomalacia, kuma yara suna iya kamuwa da rickets. Idan sinadarin calcium na jini ya ragu, za a iya samun bugun hannu da kafa, jijjiga da sauransu, wadanda kuma suke da alaka da ci gaban hakora. Yawan shan bitamin D na iya haifar da hawan calcium na jini, asarar ci, amai, gudawa, har ma da ectopic ossification na kyallen takarda.