Q: My daughter told me a boy kissed her on the bus. She's 7. Should I make a big deal out of it? --Christina, Bend, OR

A quick peck is a normal way for children to express fondness for one another, explains Neal Horen, Ph. D., a clinical psychologist at the Georgetown University Center for Child and Human Development. "They're just two second-graders who may be innocently mimicking adult behavior," he says. However, if your daughter seemed bothered by the bus-ride buss, Horen advises stressing that her personal space is like her own protective bubble, and that she's allowed to say "stop" if someone comes too close or touches her in a way she doesn't like. "At the same time," he adds, "reiterate how proud you are that she came to you about the kiss." Your positive reinforcement will encourage her to tell you about similar experiences in the future.

Q: Should my child take a multivitamin? --Jen, Scarsdale, NY

If there's a nutritional equivalent to flushing money down the toilet, this is it. Since healthy children typically ingest more vitamins and minerals from food than their bodies can actually use, the nutrients in a multi end up being expelled, explains Nicolas Stettler, M.D., M.S.C.E., a member of the American Academy of Pediatrics Committee on Nutrition. "It's very expensive urine!" he says. "Worse, fat-soluble vitamins A, E, and K can accumulate in a child's body and cause neurological, gastrointestinal, cardiovascular, and other complications." That said, there is one letter of the alphabet that many children could use more of: D. Any child who isn't drinking four eight-ounce cups of milk each day should take a daily dose of 400 international units of vitamin D3, the same form that our bodies manufacture when exposed to sunlight. "Vitamin D appears to contribute to protection against many serious diseases," Stettler says. "These include osteoporosis; multiple sclerosis; rheumatoid arthritis; breast, ovarian, and prostate cancers; and type 2 diabetes."

Q: Are 529 college-savings plans still worth it? --Cris, Montpellier, VT

Yes, they remain a smart investment. "A 529 account is like a Roth IRA, but for college savings instead of retirement," explains Gary Schatsky, the chairman emeritus of the National Association of Personal Financial Advisors. "It offers two tax advantages: no taxes on your profits, and additional state incentives such as a tax deduction or credit for putting money into the account." But state plans vary widely, so Schatsky recommends Utah's--which offers low fees and good fund selection--for those whose state doesn't offer any unique tax incentives (you don't have to stick with the plan offered by the state in which you reside). As for how you invest--the ratio of stocks to bonds--that will depend on the age of your child and your comfort level with risk.