TABLE 1.
Summary of the vitamers for each of the 13 vitamins, including information on availability of standardized methods for foods, CRMs for foods, and quantification principle for the state-of-the-art analytical method
| Vitamin | Vitamer | Standardized | CRM | State-of-the-art |
|---|---|---|---|---|
| method1, matrix2 | organization3, matrix4 | method and quantification | ||
| (organization) | principle5 | |||
| Vitamin A | Total retinol | Foods (CEN) | – | LC-UV |
| All-trans retinol | Foods (CEN) | – | ||
| 13-cis-retinol | Foods (CEN) | – | ||
| Retinol esters | IF, AN (ISO) | NISTy | ||
| Retinaldehyde | IF, AN (ISO) | – | ||
| Total β-carotene | – | ERMd | LC-VIS | |
| All-trans β-carotene | Foods (CEN) | ERMd | ||
| Total α-carotene | – | ERMd | ||
| All-trans α-carotene | – | ERMd | ||
| β-Cryptoxanthin | – | – | ||
| Vitamin D | Vitamin D-3 | Foods (CEN)/IF, AN (ISO) | ERMb/NISTy | LC-MS/MS |
| Vitamin D-2 | Foods (CEN)/IF, AN (ISO) | NISTn | ||
| 25-Hydroxyvitamin D-3 | – | NISTq | ||
| 25-Hydroxyvitamin D-2 | – | – | ||
| Vitamin E | α-Tocopherol, total | Foods (CEN/ISO) | ERMb/NISTy,m | LC-UV/LC-fluorescence |
| α-Tocopherol | IF, AN (ISO) | – | ||
| α-Tocopheryl acetate | IF, AN (ISO) | NISTy | ||
| Vitamin K | Phylloquinone, total | Foods (CEN) | NISTy | LC-fluorescence/LC-MS/MS |
| Phylloquinone, trans | Foods (CEN) | – | ||
| Phylloquinone, cis | Foods (CEN) | – | ||
| Menaquinone-4 | – | – | ||
| Menaquinone-n (MK-n) | – | – | ||
| Thiamine | Thiamine, total | Foods (CEN) | ERMa,d,e/NISTx,m | LC-fluorescence/LC-MS/MS |
| Thiamine, free | – | NISTz | ||
| Thiamine | – | – | ||
| Thiamine monophosphate | – | – | ||
| Thiamine diphosphate | – | – | ||
| Thiamine triphosphate | – | – | ||
| Riboflavin | Riboflavin, total | Foods (CEN) | ERMa,e/NISTx,n,p | LC-fluorescence/LC-MS/MS |
| Riboflavin | – | – | ||
| Flavin mononucleotide | – | – | ||
| Flavin adenine dinucleotide | – | – | ||
| Niacin | Niacin, total | Foods (CEN) | ERMc/NISTx,m,q | LC-MS/MS |
| Niacin, free | – | NISTz | ||
| Nicotinic acid (niacin) | – | NISTq | ||
| Nicotinamide | – | NISTx,y,m,p,q | ||
| Bound forms of niacin | – | – | ||
| Vitamin B-6 | Pyridoxine, total | Foods (CEN) | ERMd,e/NISTx,y,p | LC-fluorescence/LC-MS/MS |
| Pyridoxine, free | – | NISTz | ||
| Pyridoxine | – | – | ||
| Pyridoxal | – | NISTp | ||
| Pyridoxamine | – | NISTp | ||
| Pyridoxine-5′-phosphate | – | – | ||
| Pyridoxal-5′-phosphate | – | – | ||
| Pyridoxine-5′-d-glucoside | – | – | ||
| Pantothenic acid | Pantothenic acid, total | Foods (CEN) | NISTx,y,n,q | LC-MS/MS |
| Pantothenic acid | – | – | ||
| Coenzyme A | – | – | ||
| Biotin | Biotin, total | Foods (CEN) | NISTx,y | LC-MS/MS |
| Biotin | – | – | ||
| Biocytin (o-biotinyl lysine) | – | – | ||
| Folate | Folate, total | FOODs (CEN) | ERMa,d,e | LC-MS/MS |
| Folic acid | – | NISTy,m | ||
| Dihydrofolate | – | – | ||
| Tetrahydrofolate (THF) | – | – | ||
| 5-Methyltetrahydrofolate | – | – | ||
| 5-Formyltetrahydrofolate | – | – | ||
| 10-Formyltetrahydrofolate | – | – | ||
| 5,10-Methenyltetrahydrofolate | – | – | ||
| 5,10-Methylenetetrahydrofolate | – | – | ||
| 10-Formyldihydrofolate | – | – | ||
| 10-Formylfolic acid | – | – | ||
| Vitamin B-12 | Vitamin B-12, total | Foods (CEN)/IF, AN (ISO) | ERMe | LC-MS/MS |
| Cyanocobalamin | – | – | ||
| Methylcobalamin | – | – | ||
| Adenosylcobalamin | – | – | ||
| Hydroxycobalamin | – | – | ||
| Vitamin C | Vitamin C, total | IF, AN (ISO) | ERMc/NISTx,y,p | LC-UV |
| Ascorbic acid | – | – | ||
| Dehydroascorbic acid | – | – |
Standardised method in foodstuff for each vitamer or the total for a vitamin provided by CEN, European Committee for Standardisation and ISO, International Organization for Standardization; information on where to obtain (buy) CEN-methods: https://standards.cen.eu/dyn/www/f?p=CENWEB:5 or ISO-methods: https://www.iso.org/home.html
IF, Infant formula; AN, Adult nutritional
NIST, National Institute of Standards and Technology, ERM, European Reference material.
CRMs: aBCR-121, wholemeal flour; bBCR-122, margarine; cBCR-431, brussels sprouts; dBCR-485, mixed vegetables; eBCR-487, pig liver; fERM-BD600, wholemilk powder (more information at: https://crm.jrc.ec.europa.eu/). NIST: nSRM3235, soy milk; mSRM3233, fortified breakfast cereal; pSRM1549a, whole milk powder; qSRM1546a, meat homogenate; xSRM1869, infant/adult nutritional formula (milk/whey/soy-based); ySRM1849a, infant/adult nutritional formula I (milk-based); zSRM3287, blueberry (more information at: https://www-s.nist.gov/srmors/). SRM with reference values is provided in Supplemental Table 2.
LC-UV, Liquid chromatography-ultraviolet light detection; LC-VIS, Liquid chromatography-visible light detection; LC-MS/MS, Liquid chromatography-tandem mass spectrometry.