Ko te Huaora D he huaora, he homoni steroid ano hoki, ko te nuinga ko te VD2 me te VD3, he tino rite te hanganga. Ka hurihia te Huaora D3 me te D2 ki te 25 hydroxyl vitamin D (tae atu ki te 25-dihydroxyl vitamin D3 me D2). 25-(OH) VD i roto i te tinana tangata, struction pūmau, kukū tiketike. Ko te 25-(OH) VD e whakaatu ana i te tapeke o te huaora D , me te kaha o te huringa o te huaora D, no reira ko te 25-(OH)VD ka whakaarohia ko te tohu pai rawa atu mo te aromatawai i te taumata o te huaora D. Ko te Kete Tohu Whakaata kei runga immunochromatography a ka puta he hua i roto i te 15 meneti.