Table 3.
Analytical methods for some of the measurements
| Analyte | Source | Methodology |
|---|---|---|
| Vitamin A | Plasma | Spectrophotometry [80] |
| Total Carotenes (alpha, beta, epsilon, gamma) | Plasma | Spectrophotometry [81] |
| Vitamin C (sum of reduced and oxidized forms) | Plasma | Spectrophotometry [82] |
| Vitamin D3 (25-hydroxy) | plasma | Measured in plasma by liquid chromatography - tandem mass spectroscopy (LC/MS/MS) [83] |
| Vitamin E (total tocopherols, including alpha, gamma1, gamma2) | serum | Spectrophotometry [84] |
| Vitamin K | plasma | Vitamin K was extracted from plasma by methylene chloride in a monophasic design, purified on a C-18 cartridge, separated on a reversed-phase column, and then detected fluorometrically [85] |
| Thiamine | Whole Blood | Microbiological Assay [86] |
| Riboflavin | Whole Blood | Microbiological Assay [87] |
| Niacin | Whole Blood | Microbiological Assay [88] |
| Pantothenic Acid | Whole Blood | Microbiological Assay [89] |
| P5P | RBC | Microbiological Assay [90] |
| Biotin | Whole Blood | Microbiological Assay [91] |
| Folic Acid | Serum | Microbiological Assay [92] |
| Vitamin B12 | Plasma | Microbiological Assay [93] |
| Choline (Free and Total) | RBC | Microbiological Assay [94] |
| Alpha lipoic acid | Plasma | Microbiological Assay [95] |
| CoQ10 | Plasma | Reverse-phase high-performance liquid chromatography (HPLC) using hexane extraction on a C-18 column (15 cm, 5 micron) with methanol:hexane (95:5) as the mobile phase and UV detection [96] |
| Adenosine, Inosine, Uridine | Plasma | HPLC with 254 adsorption [97] |
| Formimino-glutaric acid (FIGLU) | Urine | Spectrophotometrically [98] after adjustment of specific gravity at neutral pH [99] |
| Kryptopyrole | Urine | Spectrophotometrically [100] after adjustment of specific gravity at neutral pH [99] |
| Methylmalonic Acid | Urine | Liquid chromatography - tandem mass spectroscopy (LC-MS/MS) with electrospray ionization [101], expressed per gram creatinine |
| N-methylnicotinamide | Urine | HPLC, with ultraviolet diode array detection [102], and the results are expressed per gram creatinine |
| Serum Ferritin | Serum | Immunometric assay with Immunlite 2000 (Diagnostics Product Corp., Los Angeles, California) |
| S-adenosylmethionine (SAM) and S-adenyosylhomocysteine (SAH) | RBC | Extracted from RBC [103] and measured by LCMS [104] |
| Glutathione (GSH and GSSG) | Plasma | Fluorescence detector [105] |
| Nitrotyrosine | Plasma | LCMS [106] |
| ATP | Plasma | Luciferin-luciferase assay [107] |
| NADH, NADPH | RBC | Spectrophotometry [108] |
| Sulfate (Free and Total) | Plasma | Using indirect atomic absorption spectrometry [109] |