Yes, that was Mel Gibson on TV being ambushed by a SWAT team for possession of acid ascorbic acid, that is. ''Guys, it's only vitamins,'' he pleads, hands in the air. ''Like in oranges?'' The spot, aired recently on a Palm Springs station and slated for a wider release as a public-service announcement later this month, urges health buffs to phone their lawmakers and protest a government crackdown on vitamin-supplement distribution.
''The FDA has been raiding doctors' offices and health-food stores,'' claims the ad's director, Charles Ashira. Mel, known as a vitamin C user, donated his services to the cause.