The Folic Acid and Zinc Supplementation Trial (FAZST) was a multi-center, double-blind, randomized placebo-controlled trial to assess the effects of folic acid and zinc supplementation among male partners of couples seeking assisted reproduction, on the trial’s primary outcomes of semen quality and live birth. Male participants were randomized equally (1:1) either to active study supplement (combined 5 mg folic acid and 30 mg elemental zinc) or to matching placebo. The study intervention continued for 6 months from randomization, and male participants completed in-person study visits, which included blood, urine, and semen collection, at baseline, 2, 4, and 6 months. Female partners provided biospecimens at baseline and questionnaire data, and clinical outcomes were followed through chart abstraction. Trial recruitment was completed in December 2017, with a total of 2372 couples enrolled. The Impact of Diet, Exercise and Lifestyle (IDEAL) Fertility Study involves additional detailed follow-up on a subset of the female partners. The Division of Population Health Research (DiPHR) entered into a Materials Transfer Agreement (MTA) with the University of Pennsylvania Medical School in 2021 involving 48,948 samples from the FAZST collection. In May 2022 this MTA was terminated. DiPHR acknowledges the work the repository has undertaken to prepare these samples for transfer.