There’s no end to new information about vitamin D, skin cancer, and sun protection factor (SPF) levels in sunscreen. Sun-related topics take on special importance for people with lupus. Here are five facts that will help you be safer in the sun.

1. UV rays are not all the same. When we talk about sun exposure, what we really mean is exposure to ultraviolet (UV) radiation. UV-A and UV-B are the types that most often penetrate the ozone layer to reach Earth. UV-A can trigger cutaneous lupus, and can cause flares of existing systemic lupus, says Andrew Franks Jr., MD. “UV-B is shorter—it’s the ‘burning’ ray that can damage DNA and cells. UV-A is longer and can penetrate more deeply into the middle layer of the skin,” says David Fiorentino, MD, PhD.
   
   UV rays are stronger when ozone is low, when they are reflected off of sand, snow or water, and at high altitude.
2. UV reaction can take many forms. People with lupus need to be aware of UV photosensitivity. “Photosensitivity could mean a systemic response, like feeling sick, having chills, fever, even joint pain, or that you sunburn more easily,” Fiorentino says. Sometimes, though, the photosensitivity reaction may not be visible. UV-A rays can affect the DNA in the blood vessels without causing a sunburn or other external signs of the exposure. “You don’t necessarily know when the damage has been done until it’s too late,” Franks warns.
3. There’s no such thing as a “safe” tan from UV light. One of the most dangerous myths about UV rays is that damage occurs only after a sunburn. The idea that a “base tan” will prevent burning and, therefore, prevent illness is particularly troublesome. “Any time you have a tan, it means your skin is trying to protect itself from further damage by producing melanin,” Fiorentino says. Tanning beds, which use UV-A rays, are especially dangerous. To date, at least 44 states and the District of Columbia regulate indoor tanning for minors, while 16 states ban the use of UV tanning devices by anyone under age 18. Other state laws combine various restrictions.
   
   For a tanned look, tanning products are the way to go. Cosmetic bronzers wash off like regular makeup; sunless tanners temporarily stain the skin. But remember: The “tan” you get with these products does not provide UV protection.
4. Vitamin D doesn't have to come from the sun. For people with lupus, vitamin D is a real concern. “It’s high on everyone’s radar and with good reason,” Fiorentino says. “UV-B is required for the body to make vitamin D, so if you use sunscreen or clothing that decreases your UV-B exposure, you decrease the vitamin D that your body makes.” To meet your daily vitamin D requirement without spending extra time in the sunlight, you can eat foods with vitamin D or take vitamin supplements. For most people, the National Institutes of Health recommends 600 international units (IUs) per day, though your doctor may recommend up to 1,000 IUs. “It’s much easier and safer to supplement with vitamins, especially since it’s hard to recommend any sun exposure beyond what people with lupus get in day-to-day life,” Fiorentino says.
5. Effective sun protection requires more than sunscreen. The sun is the primary outdoor source of UV light, but UV rays can also affect you indoors and in cars. “The biggest risk is often when the sun comes through windows,” Fiorentino explains. While glass does block UV-B transmission, most UV-A gets through. Tinting for car windows is regulated state by state; check with your motor vehicle department. Window film for your home is also available from various manufacturers.
   
   Other UV sources can be harder to spot. Franks says the new flat computer and television screens do not emit radiation, but older models do. The bigger concern is lighting. “Halogen and fluorescent lights emit more radiation than incandescent,” he says. If the bulb is exposed, especially a halogen bulb, “people who are photosensitive can have problems if they are within four feet of it,” he says. “You can, however, completely block UV with plastic covers.” 

You can protect yourself best with a combination of:  

• sun-protective clothing, including broad-brimmed hats and sunglasses 
• sunscreen used correctly and consistently (the Mexoryl-based sunscreens are the most effective against UV-A, says Franks, but choose products that block both UV-A and UV-B) 
• planning your outdoor activities for early in the morning and late in the afternoon, and seeking shade whenever possible

Talk to your doctor about any other steps you can take to limit your UV exposure.