it was 2500 mg of vitamin c. The study is Tawasri, P. Ampasavate, C., et al, Effect of Oral Coadministration of Ascorbic Acid with Ling Zhi Preparation on Pharmacokinetics of Ganoderic Acid A in Healthy Male Subjects: A Randomized Crossover Study, BioMed Res Int, 2016;2819862, 7 pp.