I have heard that the foods you eat can help your body thwart more of the UV rays it may be exposed to, (remember flourescent bulbs indoors produce UV rays too!) . Here are 2 great articles on the subject. Eat your watermelon and tomatoes (if tolerated) and any other high lycopene foods for natural sun protection from the inside, out!
***MAKE SURE that you cover up with UV rated clothes/hats or use sun screen if you have Lupus, don't rely ONLY on foods you eat for sun protection***