Folate absorption from folate-fortified and processed foods using a human ileostomy model.
Data on folate absorption from food from validated human studies using physiological folate doses are still needed to estimate dietary requirements and to formulate recommendations. The aim of the present work was to study the effects from fortified and processed foods on folate absorption in ileostomy volunteers (n 9) using the area under the plasma concentration curve (AUC) and kinetic modelling. Using a standardized single-dose protocol, dairy products fortified with a candidate fortificant (6S)-5-methyltetrahydrofolate ((6S)-5-CH3-H4folate), folic acid-fortified bread and a dessert crème containing natural yeast folate polyglutamates were compared with folate supplements. Absorbed folate was estimated by AUC and a kinetic model, and non-absorbed folate by ileostomal folate excretion. Median apparent absorption from test foods ranged from 55 to 86 %. Added folate-binding proteins (FBP) significantly reduced folate absorption from dairy products, as in the absence of FBP, AUC-dose-corrected ratios were increased and ileal folate excretion decreased. After in vivo gastrointestinal passage of dairy products containing FBP, up to 43 % of the ingested FBP was found in ileostomal effluent. Folate absorption was similar for (6S)-5-CH3-H4folate fortificant from fermented milk and for folic acid from fortified bread. Folic acid, ingested as food fortificant in bread, was significantly less absorbed compared with an isolated supplement. We conclude that all tested foods were suitable matrices for folate fortification. However, dairy products, fortified with the new candidate fortificant (6S)-5-CH3-H4folate, are suitable if no active FBP is present.
Witthöft
Cornelia M
CM
Department of Food Science, Swedish University of Agricultural Sciences, P.O. Box 7051, SE-75007 Uppsala, Sweden. Cornelia.Witthoft@lmv.slu.se
Arkbåge
Karin
K
Johansson
Madelene
M
Lundin
Eva
E
Berglund
Gerd
G
Zhang
Jie-Xian
JX
Lennernäs
Hans
H
Dainty
Jack R
JR
D000042:Absorption; D000368:Aged; D019540:Area Under Curve; D001939:Bread; D003611:Dairy Products; D004032:Diet; D004044:Dietary Proteins / Q000378:metabolism; D005260:Female; D005492:Folic Acid / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine; D005511:Food Handling / Q000379:methods*; D005527:Food, Fortified; D006801:Humans; D007081:Ileostomy; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D011624:Pteroylpolyglutamic Acids / Q000378:metabolism; D013763:Tetrahydrofolates / Q000008:administration & dosage / Q000493:pharmacokinetics
D004044:Dietary Proteins; D011624:Pteroylpolyglutamic Acids; D013763:Tetrahydrofolates; D005492:Folic Acid