Inhibition of Folic Acid Uptake by Catechins and Tea Extracts in Caco-2 Cells - Alemdaroglu, N Ceren; Wolffram, Siegfried; Boissel, Jean-Paul; Closs, Ellen; Spahn-Langguth, Hildegard; Langguth, Peter (Planta Medica, 2007)