Cov vitamins, qee zaum transliterated li vitamins, yog ib lub ntsiab lus tshwj xeeb hauv kev noj haus. Lawv xa mus rau ntau cov organic tebchaw thiab yog ib chav kawm ntawm cov kab mob organic uas tsim nyog rau tib neeg thiab tsiaj txhu kom tswj tau lub cev lub cev. Feem ntau tsis tuaj yeem tsim los ntawm lub cev nws tus kheej thiab yuav tsum tau txais los ntawm cov khoom noj. Tsuas yog ob peb tus tuaj yeem ua ke hauv lub cev lossis tsim los ntawm cov kab mob hauv plab hnyuv. Lawv ua lub luag haujlwm tseem ceeb hauv tib neeg txoj kev loj hlob, metabolism, thiab kev loj hlob thiab yog ib qho ntawm 6 cov khoom noj tseem ceeb (carbohydrates, rog, proteins, minerals, vitamins, thiab dej). Cov vitamins tsis koom nrog kev tsim cov hlwb hauv tib neeg lossis muab lub zog rau lub cev, tab sis lawv koom nrog cov tshuaj biochemical hauv lub cev thiab tswj lub cev cov metabolism hauv lub cev. Yog tias kev noj cov vitamins tsis txaus, nws yuav ua rau muaj kev tsis txaus ntseeg hauv tib neeg cov metabolism, ua rau muaj kev tiv thaiv tsis zoo thiab ua rau "vitamin deficiency." Cov vitamin deficiency hauv thawj zaug tuaj yeem tshwm sim los ntawm kev noj zaub mov tsis txaus vim tsis muaj cov vitamins hauv cov zaub mov lossis txo cov zaub mov noj.
Secondary vitamin deficiency tuaj yeem tshwm sim los ntawm qhov tsis muaj peev xwm ntawm lub cev kom nqus cov vitamins, xav tau cov vitamins ntxiv, lossis cuam tshuam los ntawm qee cov tshuaj. Cov vitamins yog ib tsev neeg loj, muaj ntau lub npe tam sim no. Lawv tuaj yeem muab faib ua ob pawg loj: rog-soluble thiab dej-soluble. Dej- cov vitamins soluble yog yooj yim soluble nyob rau hauv dej tab sis tsis nyob rau hauv non-polar organic solvents. Tom qab nqus tau, tsawg heev yog khaws cia rau hauv lub cev, nrog ntau dhau raug tso tawm hauv cov zis. Rog- cov vitamins soluble yog yooj yim soluble nyob rau hauv non{10}}polar organic solvents tab sis tsis nyob rau hauv dej. Lawv tuaj yeem nqus tau los ntawm lub cev nrog rau cov rog thiab khaws cia hauv lub cev, nrog rau qhov qis qis. Txhua cov vitamin feem ntau dhau los ua ntau yam tshuaj tiv thaiv, yog li cov vitamins feem ntau muaj ntau yam haujlwm. Cov vitamins A, D, E, thiab K yog rog- cov vitamins soluble, thaum cov vitamins B thiab C yog dej- cov vitamins soluble. Qee cov tshuaj muaj tshuaj zoo ib yam li qee cov vitamins thiab tuaj yeem hloov mus rau hauv cov vitamins los ntawm cov tshuaj metabolic yooj yim. Cov tshuaj no hu ua provitamin. Piv txwv li, -carotene tuaj yeem hloov mus rau hauv vitamin A; 7-dehydrocholesterol tuaj yeem hloov mus rau hauv vitamin D3, tab sis qhov no yuav tsum muaj ntau yam kev cuam tshuam metabolic. Tryptophan, ib feem ntawm nicotinic acid, tsis tuaj yeem suav hais tias yog provitamin.