Americans are buying more fish-oil supplements than ever ... and in two samples of Nature's Bounty. Most tested pills are claimed to be "purified" or "free" of PCBs, mercury, or other contaminants ...

Narrator: Vitamins ... This is the fish aisle. Next is the encapsulation area. The freshly made gel ribbons first go through a bath of oil, which acts as a glue to help form the softgel.