gnc mega men sport daily multivitamin for performance, muscle function, and general health -180 count gnc clinically studied multivitamin - performance - supports muscle function - contains antioxidants with over 30 clinically studied ingredients in every formula and more antioxidant power than ever are in smaller, easier to swallow pills. men's health contains a clinically studied men's multivitamin shown to work better than a basic multivitamin. helps support colon and prostate health. performance features beta-alanine, a high-efficiency muscle ph buffer, and carnitine, which helps use fatty acids as energy. muscle function features branched chain amino acids to fuel muscles. also supports muscles by providing essential electrolytes that may be lost during intense exercise, including calcium, which plays a role in mediating muscle contraction. antioxidants packed with antioxidants to help fight free radicals that can be produced during your workout. ^in a randomized, double blind, placebo-controlled study of 112 healthy volunteers, subjects taking the gnc vitamin and mineral blends for six weeks experienced significant improvements in serum levels of certain key ingredients compared to a placebo and a leading multivitamin formula based upon multivariate statistical analysis of a group of b vitamins (thiamin, niacin, riboflavin, pantothenic acid, biotic, folic acid and vitamins b-6 and b-12) and key antioxidants and carotenoids (a group of beta-carotene, alpha tocopherol, selenium, lutein and lycopene). statistical improvements in sf-36 vitality and mental health scored were also observed compared to placebo.