The sun gives us daylight, solar energy, and photosynthesis, but it also causes sunburns, aging of the skin, and some skin cancers. Sunscreen is the antidote--hailed as the protector against burns, wrinkles, and skin disease.

But are the ingredients in sunscreen themselves dangerous? Which is worse: the sun with its UVA and UVB rays or the sunscreen we use to protect against them?

There are two types of UV light emitted by the sun that actually reach us here on earth: UVA and UVB. A suntan generally comes from UVB exposure. UVB causes the skin to produce vitamin D which, in turn, helps the body to utilize calcium and build strong bones. But the UVB waves also cause direct DNA damage, turning some cells cancerous. So sunblock was originally designed to protect against UVB.

Until the late 1980s, UVA was thought to be the sun's "safe" ray. In fact, it can be used therapeutically, particularly among patients with skin diseases like psoriasis and vitiligo. But as it turns out, UVA is not as benign as once thought. Studies show a correlation between sun exposure and the most deadly skin cancer, melanoma.

Regardless of the upsides of UV light, it still seems that anything you can do to protect yourself from the sun's harmful rays would be helpful. This is because skin cancer is the most common form of cancer diagnosed in the US and more than 90% of all skin cancers are known to be caused by sun exposure. Certainly avoiding sun exposure during peak hours (10am until 2-4pm, depending upon where you live), and wearing long sleeves and long pants will help. But what if it is 100 degrees and long clothing is too hot? What if your child is at summer camp, playing in the good ol' outdoors? Sunscreen is the safest alternative, right? Not everyone thinks so.

Read more from Dr. Cara.

Dr. Cara Natterson, author of Your Toddler: Head To Toe, is a pediatrician and mother of 2. To buy a copy, click here. She is currently working on the forthcoming book entitled Dangerous or Safe?