title: Increases in blood folate indices are similar in women of childbearing age supplemented with [6S]-5-methyltetrahydrofolate and folic acid.
abstract: The natural diastereoisomer [6S]-5-methyltetrahydrofolate ([6S]-5-MTHF) may be a safer fortificant than folic acid for neural tube defect (NTD) prevention because it is unlikely to mask vitamin B-12 deficiency. An inverse relationship between NTD risk and blood folate concentrations has been reported. In this randomized, placebo-controlled, double-blind trial, we compared the effects of [6S]-5-MTHF and folic acid supplementation for 24 wk on plasma folate and red cell folate (RCF) in women of childbearing age (18-49 y). Women (n = 104) were randomly assigned to receive a supplement containing [6S]-5-MTHF (113 micro g/d), folic acid (100 micro g/d) or placebo. The mean estimated linear increase in plasma folate concentration was 0.3 [95% confidence interval (CI): 0.1, 0.5], and 0.4 (0.2, 0.6) nmol/(L. wk) in the [6S]-5-MTHF and folic acid groups, respectively. The mean estimated linear increase in RCF was 7.4 (95% CI: 4.5, 10.3), and 8.3 (4.4, 12.3) nmol/(L. wk) in the [6S]-5-MTHF and folic acid groups, respectively. There were no differences in the slopes between the [6S]-5-MTHF group and the folic acid group in either plasma folate (P = 0.48) or RCF (P = 0.70). At 24 wk, estimated mean increases in plasma folate concentrations were 6.9 (95% CI: 1.7, 12.2) and 9.2 (3.3, 15.1) nmol/L, and in RCF, 251 (143, 360) and 275 (148, 402) nmol/L, in the [6S]-5-MTHF and folic acid groups, respectively, relative to the placebo group. These data suggest that low dose [6S]-5-MTHF and folic acid supplementation increase blood folate indices to a similar extent. A steady state in the blood indices had not been reached by 24 wk.
authors.affiliation: Department of Human Nutrition and. Preventive and Social Medicine University of Otago, Dunedin, New Zealand.
authors.forename: Bernard J
authors.initials: BJ
authors.lastname: Venn
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Green
authors.forename: Rudolf
authors.initials: R
authors.lastname: Moser
authors.forename: Joanne E
authors.initials: JE
authors.lastname: McKenzie
authors.forename: C Murray
authors.initials: CM
authors.lastname: Skeaff
authors.forename: Jim
authors.initials: J
authors.lastname: Mann
mesh_terms: D000293:Adolescent; D000328:Adult; D019587:Dietary Supplements; D004311:Double-Blind Method; D004912:Erythrocytes / Q000737:chemistry; D005260:Female; D005492:Folic Acid / Q000008:administration & dosage* / Q000097:blood*; D006801:Humans; D008875:Middle Aged; D010919:Placebos; D013237:Stereoisomerism; D013763:Tetrahydrofolates / Q000008:administration & dosage*
chemical_list: D010919:Placebos; D013763:Tetrahydrofolates; D005492:Folic Acid; C005984:5-methyltetrahydrofolate