"The truth," Elvis Presley once said, "is like the sun. You can shut it out for a while, but it ain't going away." And the truth about the sun? It's a source of health (reduces blood pressure, helps the body make vitamin D) and happiness (it elevates your mood), but you gotta shut it out, over and over, especially when it comes to babies and toddlers.

Early exposure to sun can set up an infant for skin cancer woes later in life.

Rule No. 1: Babies younger than 6 months should be kept out of the sun, by avoiding midday rays and using protective clothing, hats and umbrellas. It's NOT a good idea to use sunscreens on babies' easily permeable skin; the safety is unknown.

Rule No. 1B: Since you're avoiding the sun, ask your pediatrician about vitamin D-3 supplements for your baby. The American Academy of Pediatrics recommends 400 IU vitamin D a day until babies can drink 32 ounces of D-fortified formula daily.

Rule No. 2: Start using sunscreen (remember ears, lips, toes, fingers) when your child becomes mobile. Test for sensitivity before doing an all-over rub; reapply every 30 minutes. And provide wraparound sunglasses that filter out UVA and UVB rays.

Rule No. 3: If your toddler starts to look "a little pink," it's PAST time to get out of the sun. It can take 12 hours for a burn to show up, and by then it's too late to avoid the damage.For more information, go to Sharecare.com; the experts this month are discussing skin cancer prevention.