Skip to main content

Table 1 Micronutrient assay methods.

From: Usage patterns, health, and nutritional status of long-term multiple dietary supplement users: a cross-sectional study

Analyte Method Ref.
RBC folate (nmol/L) Quantaphase Folate Radioassay Kit, Bio-Rad Laboratories 7
Retinol (μg/dL) Isocratic reversed-phase HPLC with UV/Vis detection 8
Ascorbic acid (mg/dL) Isocratic reversed-phase HPLC with Electrochemical detection* 7
Alpha tocopherol (mg/dL) Isocratic reversed-phase HPLC with UV/Vis detection 8
Alpha carotene (μg/dL) Isocratic reversed-phase HPLC with UV/Vis detection 8
Beta carotene (μg/dL) Isocratic reversed-phase HPLC with UV/Vis detection 8
Ferritin (μg/L) Quantlmune Ferritin IRMA kit, Bio-Rad Laboratories 7
25-hydroxyvitamin D (nmol/L) Quantlmune Ferritin IRMA kit, Bio-Rad Laboratories 7
Homocysteine (μmol/L) Isocratic reversed-phase HPLC with Fluorescence detection 9
C-reactive protein (mg/L) Latex-enhanced nephelometry, Behring Nephelometer Analyzer for NHANES assays and Hitachi 917 Analyzer for Multiple Supp user assays 7
Total cholesterol (mg/dL) Timed endpoint, coupled enzymatic methodology 10
LDL-cholesterol (mg/dL) Calculated** 7
HDL-cholesterol (mg/dL) Polyanion/divalent cation precipitation of other lipoproteins followed by timed endpoint, coupled enzymatic methodology 10
Triglycerides (mg/dL) Timed endpoint, coupled enzymatic methodology 11
  1. *Use of 1 part serum plus 1 part 10% meta-phosphoric acid for Multiple Supp users versus NHANES use of 1 part serum plus 4 part meta-phosphoric acid.
  2. ** Calculated: LDL-cholesterol = [total cholesterol - HDL-cholesterol - (triglycerides/5)] Ref = reference, LDL = low-density lipoprotein, HDL = high-density lipoprotein.