title: Effect of folic Acid supplementation on the folate status of buccal mucosa and lymphocytes.
abstract: Folate deficiency may be associated with an increased risk of cancer at certain sites. There is a need to measure folate status and putative biomarkers of cancer risk in the same target tissue, or in surrogate tissues. A study was carried out to develop a method for the rapid measurement of folate in human buccal mucosa and lymphocytes and to evaluate the responsiveness of this measurement in both tissues to folic acid supplementation in healthy subjects, relative to conventional markers of folate status. Three hundred and twenty-three adults, ages between 20 and 60 years, were screened for RBC folate concentrations. Sixty-five subjects with red cell folate between 200 and 650 nmol/L participated in a randomized, double blind, placebo-controlled, folic acid (1.2 mg) intervention trial, lasting 12 weeks. As anticipated, a significant baseline correlation (r = 0.36, P < 0.01) was observed between red cell folate and plasma 5-methyltetrahydrofolate (5-MeTHF). Lymphocyte total folate was significantly associated with plasma 5-MeTHF (r = 0.28, P < 0.05) and plasma total homocysteine concentration (r = -0.34, P < 0.05). Buccal mucosa total folate showed no correlation with either red cell folate or 5-MeTHF, but was significantly associated with lymphocyte total folate (r = 0.35, P < 0.01). Supplementation elicited a significant increase in lymphocyte total folate (P < 0.01), and this was strongly associated with the increase in RBC total folate (P < 0.01) and plasma 5-MeTHF (P < 0.01). Buccal mucosa total folate was not influenced by folate supplementation. Methods have been developed for the rapid measurement of lymphocyte and buccal mucosal total folate. Lymphocyte folate is sensitive to folate intake and is reflected by plasma 5-MeTHF.
authors.affiliation: Human Nutrition Unit, University of Sheffield, Coleridge House, Northern General Hospital, United Kingdom.
authors.forename: Graham P
authors.initials: GP
authors.lastname: Basten
authors.forename: Marilyn H
authors.initials: MH
authors.lastname: Hill
authors.forename: Susan J
authors.initials: SJ
authors.lastname: Duthie
authors.forename: Hilary J
authors.initials: HJ
authors.lastname: Powers
mesh_terms: D000293:Adolescent; D000328:Adult; D014408:Biomarkers, Tumor / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D004249:DNA Damage; D019587:Dietary Supplements; D004912:Erythrocytes / Q000187:drug effects*; D005260:Female; D005492:Folic Acid / Q000097:blood* / Q000494:pharmacology*; D006710:Homocysteine / Q000097:blood / Q000187:drug effects; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects*; D008297:Male; D008875:Middle Aged; D009061:Mouth Mucosa / Q000187:drug effects*; D013763:Tetrahydrofolates / Q000097:blood
chemical_list: D014408:Biomarkers, Tumor; D013763:Tetrahydrofolates; D006710:Homocysteine; D005492:Folic Acid; C005984:5-methyltetrahydrofolate