Folate status and concentrations of serum folate forms in the US population: National Health and Nutrition Examination Survey 2011-2.
Autor: | Tsz Yan Wong, Shu-Mei Lin, Leung, Lai K. |
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Předmět: |
ERYTHROCYTES
BIOMARKERS CONFIDENCE intervals FOLIC acid HIGH performance liquid chromatography INTERVIEWING MASS spectrometry MICROBIOLOGICAL techniques PROBABILITY theory QUESTIONNAIRES RESEARCH funding STATISTICAL sampling STATISTICS SURVEYS DATA analysis CROSS-sectional method DATA analysis software DESCRIPTIVE statistics |
Zdroj: | British Journal of Nutrition; 6/28/2015, Vol. 113 Issue 12, p1965-1977, 13p |
Abstrakt: | Serum and erythrocyte (RBC) total folate are indicators of folate status. No nationally representative population data exist for folate forms. We measured the serum folate forms (5-methyltetrahydrofolate (5-methylTHF), unmetabolised folic acid (UMFA), non-methyl folate (sum of tetrahydrofolate (THF), 5-formyltetrahydrofolate (5-formylTHF), 5,10-methenyltetrahydrofolate (5,10-methenylTHF)) and MeFox (5-methylTHF oxidation product)) by HPLC-MS/MS and RBC total folate by microbiologic assay in US population ≥ 1 year (n approximately 7500) participating in the National Health and Nutrition Examination Survey 2011-2. Data analysis for serum total folate was conducted including and excluding MeFox. Concentrations (geometric mean; detection rate) of 5-methylTHF (37.5 nmol/l; 100%), UMFA (1.21 nmol/l; 99.9%), MeFox (1.53 nmol/l; 98.8%), and THF (1.01 nmol/l; 85.2%) were mostly detectable. 5-FormylTHF (3.6%) and 5,10-methenylTHF (4.4%) were rarely detected. The biggest contributor to serum total folate was 5-methylTHF (86.7%); UMFA (4.0%), non-methyl folate (4.7%) and MeFox (4.5%) contributed smaller amounts. Age was positively related to MeFox, but showed a U-shaped pattern for other folates. We generally noted sex and race/ethnic biomarker differences and weak (Spearman's r< 0.4) but significant (P< 0.05) correlations with physiological and lifestyle variables. Fasting, kidney function, smoking and alcohol intake showed negative associations. BMI and body surface area showed positive associations with MeFox but negative associations with other folates. All biomarkers showed significantly higher concentrations with recent folic acid-containing dietary supplement use. These first-time population data for serum folate forms generally show similar associations with demographic, physiological and lifestyle variables as serum total folate. Patterns observed for MeFox may suggest altered folate metabolism dependent on biological characteristics. [ABSTRACT FROM AUTHOR] |
Databáze: | Complementary Index |
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