Absorption, Metabolism, and Excretion of Riboflavin-5′-phosphate in Man

Identification and functional characterization of a novel human and rat riboflavin transporter, RFT1

“…The absorption of riboflavin from foods takes place predominantly in the small intestine through an active carrier-mediated transport process (17,24,41). In addition, carrier-mediated absorption in the colon is thought to be important, because riboflavin is synthesized by bacterial metabolism in the colon (21,44).…”

“…In vivo, in situ, and membrane vesicle experiments have elucidated the predominant role of carrier-mediated absorption in the intake of riboflavin by the small intestine and colon (4,7,17,21,24,34,41,44). In addition, the subject of riboflavin excretion has gained increasing attention.…”

Effects of short-term folic acid and/or riboflavin supplementation on serum folate and plasma total homocysteine concentrations in young Japanese male subjects

“…The subjects took their supplements three times a day just after each meal. Since, it has been recognized that oral administration of the vitamin just after a meal is more effective for its absorption than in fasting state, and that higher doses of riboflavin increases urinary excretion rate of riboflavin (Jusco and Levy, 1967). Furthermore, we considered that administration of supplements just after each meal would make subjects remember to take it properly.…”

Riboflavin Transporters RFVT/SLC52A Mediate Translocation of Riboflavin, Rather than FMN or FAD, across Plasma Membrane

“…In vivo, in situ, and membrane vesicle experiments have suggested that riboflavin transporters are essential for the maintenance of riboflavin homeostasis to constantly keep the blood and tissue concentrationsofriboflavin. [2][3][4][5][6] Human riboflavin transporters (hRFVTs), such as hRFVT1-3 encoded by SLC52A1-3 genes, have been identified. [7][8][9][10] We have revealed the functional properties of the RFVT family by comparing their functional and molecular characteristics with each other.…”