Patti Neighmond

Creatine, a chemical constituent of meat and fish that's legally been sold online, in supermarkets, health food stores and vitamin shops for at least a couple of decades, may be the most commonly used muscle-building supplement marketed.

A full decade after the Food and Drug Administration approved a vaccine to fight the sexually transmitted, cancer-causing human papillomavirus, almost half of all adolescents have still not received their first dose. This low vaccination rate is dramatic when compared to other routine childhood immunizations like polio and measles, mumps and rubella, where compliance is above 90 percent.

Every year when Morton Pollner had his checkup, he worried that doctors would find something on his lung. For years, they didn't. Then his luck ran out.

"My reaction was, 'Well, you smoked for 30 years. You got away with it for another 30 years and this is it.' I thought it was a death sentence," he says.

Peanut allergies can be among a parent's biggest worries, though we've had good evidence for more than a year that when most babies are 6 months old or so, introducing foods that contain finely ground peanuts can actually reduce babies' chances of becoming allergic to the legumes. Even so, many parents are scared to do that.

There are rating systems for hospitals, nursing homes and doctors. So why is it so hard to compare providers of child care?

Part of the reason is that there are no nationally agreed-upon standards for what determines the quality of child care. The standards that do exist are formulated in each state, and they vary widely.

For example, some states require that child care workers have a teaching certificate. Others require certain college courses. Some have strict ratios of how many caregivers are required per child.