Nws yog ib hom organic acid, yog ib yam khoom ntawm cov kab mob metabolic, binary acid, dav faib nyob rau hauv cov nroj tsuag, tsiaj txhu thiab fungi, thiab nyob rau hauv cov kab mob sib txawv ua si sib txawv.Nws tau pom tias oxalic acid yog nplua nuj nyob rau hauv ntau tshaj 100 hom nroj tsuag, tshwj xeeb tshaj yog spinach, amaranth, beet, purslane, taro, qos yaj ywm qab zib thiab rhubarb.Vim tias oxalic acid tuaj yeem txo qhov bioavailability ntawm cov ntxhia hauv cov ntsiab lus, nws raug suav tias yog ib qho antagonist rau kev nqus thiab siv cov ntxhia hauv cov ntsiab lus.Nws cov anhydride yog carbon sesquioxide.