We're drowning in neutraceuticals, which are unregulated and often make ridiculous health claims—which is probably the key reason why they've become a $23 billion industry.
The bubbles show a given supplement, and the health benefit in confers. The higher the bubble on the chart, the more evidence there is for its effectiveness. Some supplements appear more than once—for example, omega 3—because they might have multiple effects. And each of those has varying amounts of scientific back-up.