Comparison of (6S)-5-methyltetrahydrofolic acid versus folic acid as the reference folate in longer-term human dietary intervention studies assessing the relative bioavailability of natural food folates: comparative changes in folate status following a 16-week placebo controlled study in healthy adults

Wright A. J. A., King M. J., Wolfe C. A., Powers H. J., Finglas P. M.. (2010)

British Journal of Nutrition, 103, 724-729