I am sure covering your body with anything will protect you from the sun, but I think if you're looking for a natural sunblock, mud is about the best there is.
I know people who put CO on their skin, hair, etc. to make it softer, but I never heard of the sunscreen thing. I just eat it.
Stumbled into Primal due to food allergies, and subsequent elimination of non-primal foods.
Start Gluten-Free/Soy-Free: December 2012; start weight 158lbs, Ladies size 6
Start Primal: March 2013, start weight 150lbs, Ladies size 6
Current: 132lbs, Ladies size 2
26lbs lost since cutting the crap.