The study was no good. Too many people quit the study.
FWIW, the article is based upon three different studies. The only one of the three that had problems with nonadherence and withdrawal was Oral High-Dose Multivitamins and Minerals After Myocardial Infarction: A Randomized Trial.
The other two, Long-Term Multivitamin Supplementation and Cognitive Function in Men: A Randomized Trial and Vitamin and Mineral Supplements in the Primary Prevention of Cardiovascular Disease and Cancer: An Updated Systematic Evidence Review for the U.S. Preventive Services Task Force did not have this same limitation.