I ka ho?omaka ?ana o nā makahiki 1930, ua ?ike nā ?epekema ?o ka ?ike ?ana i ka lā a i ?ole ka ?ai ?ana i ka aila ?oliva, ka ?aila flaxseed, a me nā mea?ai ?ē a?e i ho?omālamalama ?ia e UV hiki ke hakakā i ka osteoporosis. ?O nā noi?i hou a?e a nā ?epekema i ?ike a kapa ?ia ka hua?a D ma ke ?ano he mea hana i loko o ke kino kanaka no ka hakakā ?ana i ka osteoporosis.

?O ka Vitamin D (VD no ka pōkole) he hua?a momona hiki ke ho?ohehe?e ?ia, ?o ia ka hui o nā derivatives steroid me nā hopena anti rickets a me nā hale like. ?O nā mea nui loa, ?o ia ka vitamina D3 (cholecalciferol, cholecalciferol) a me ka vitamina D2 (calciferol). Loa?a ka Vitamin D i ka mea?ai mai nā mea?ai holoholona e like me ke ake o ka i?a, ka hua manu, ka pata, a pēlā aku. Ho?ololi ?ia ia i 1,25-dihydroxyvitamin D3 e ka ate, kidney, a me ka mitochondrial hydroxylase, nona ka hana biological a hiki ke ho?oulu i ka synthesis o ka calcium binding protein (CaBP) i loko o ka mucosa intestinal, ho?oikaika i ka absorption calcium, a ho?oikaika i ka calcification iwi. ?O 7-dehydrocholesterol, he cholesterol derivative i loko o ke kino kanaka, mālama ?ia ma lalo o ka ?ili a hiki ke ho?ololi ?ia i cholecalciferol ma lalo o ka lā a i ?ole ka radiation ultraviolet. He hua?ai D endogenous ia e hāpai i ka absorption o ka calcium a me ka phosphorus.

?O ka VD kahi hua?ōlelo o nā steroids. He aniani ke?oke?o, hiki ke ho?ohehe?e ?ia i loko o ka momona, me nā waiwai pa?a, ke kūpa?a wela ki?eki?e, antioxidant, ?a?ole kū i ka waikawa a me ka alkali, a hiki ke luku ?ia e ka momona momona. ?O ka ate holoholona, ??ka ?aila ate i?a, a me ka ?eke hua manu he waiwai nui. ?O ka koi o kēlā me kēia lā no nā pēpē, nā keiki, nā ?ōpio, nā wahine hāpai, a me nā makuahine hānai he 400 IU (nā ?āpana honua). Ke nele, hiki i nā mākua ke loa?a i ka osteomalacia, a hiki i nā keiki ke loa?a i ka rickets. Inā emi ka calcium o ke koko, hiki i ka lima a me ka wāwae ke ku?i, ka convulsion, a me nā mea ?ē a?e, pili pū kekahi i ka ulu ?ana o nā niho. ?O ka lawe nui ?ana i ka hua?a D hiki ke ho?oulu i ke koko ki?eki?e o ka calcium, ka pau ?ana o ka ?ai, ka lua?i ?ana, ka ma?i ma?i, a me ka ectopic ossification o nā ?i?o palupalu.