Comparative human intestinal bioavailability of vitamin B-6 from a synthetic and a natural source.

Intraluminal perfusion of human jejunum has not been previously reported to demonstrate differences in bioavailability of vitamins from a food product. In this report, a triple lumen tube with a 30 cm study segment was used to study water soluble vitamin absorption in 15 normal subjects serving as their own controls. The intestinal uptake of vitamin B-6 from organ juice (O) and from a synthetic solution (S) perfused at 7.6 ml/minute were compared. In a separate series of perfusions in six subjects, the absorption of a mixture pf pyridoxine, pyridoxal, and pyridoxamine from O and S solutions with and without glucose were compared. Mean vitamin B-6 absorption was significantly greater from S (65% uptake, transport rate 0.71 mug/cm/hour) than from 9 (30% uptake, transport rate 0.40 mug/cm/hour, p less than 0.05). The addition of glucose to S enhanced this difference. Triple lumen intestinal perfusion can be used to discriminate difference in bioavailability of water soluble vitamins from natural and synthetic sources.