A survey of noninstitutionalized adults residing in the United States shows that use of multivitamin was on the decline from 37% adults using multivitamin in 1999-2000 to 31% in 2011-2012.  On the other hand, use of fish oil increased from 1.3% to 12% and Vitamin D supplementation (not from multivitamin) increased from 5.1% to 19%.Elizabeth D. Kantor; Colin D. Rehm; Mengmeng Du, ScD; et al Emily White; Edward L. Giovannucci, Trends in Dietary Supplement Use Among US Adults From 1999-2012, JAMA. 2016;316(14):1464-1474. doi:10.1001/jama.2016.14403