Suntan lotion, also known as sunscreen, shields your skin from the sun’s harmful ultraviolet radiation. By absorbing and/or reflecting dangerous UVA and UVB rays, sunscreen helps protect you from skin cancers, explains the U.S. Environmental Protection Agency. Despite its benefits, however, suntan lotion may cause health problems. Read labels carefully and use as directed to avoid dangers associated with sunscreen.
Suntan lotion may contain chemical ingredients that absorb UVA and UVB radiation, and these chemicals may cause an allergic reaction if you have sensitive skin. The EPA notes that sunscreens containing para-aminobenzoic acid, or PABA, and benzophenones are most likely to cause a reaction such as redness, itching, stinging, swelling or rash. Avoid suntan lotions that contain these ingredients if you are prone to skin allergies, and perform a skin patch test whenever you use a new brand of sunscreen.
In addition to causing allergic reactions, benzophenones in suntan lotion generate cell-damaging free radicals when exposed to sunlight. In the October 2006 volume of “Free Radical Biology and Medicine,” Dr. Kerry Hanson explains that the cell-damaging reaction occurs when sunscreen penetrates into the deeper layers of your skin. Without frequent application of fresh sunscreen to block UV rays from reaching the absorbed benzophenones, free radicals may cause cellular injury beneath your skin’s surface. Reapply suntan lotion every two hours, or more often after swimming or sweating, if you choose a sunscreen containing benzophenones.
Sunscreen may contain titanium dioxide, an ingredient that physically blocks harmful UV rays by reflecting them away from the skin. These chemically inert nanoparticles, while helpful in minimizing sun exposure, cause respiratory cancer in rats and genetic damage in mice, according to Dr. Robert Schiestl in the November 2009 volume of “Cancer Research.” Nanoparticles do not absorb through the skin, but they may be inhaled when using a spray-on sunscreen. Choose a lotion-based sunscreen to avoid potential exposure to nanoparticles.
Vitamin D Deficiency
Vitamin D is a nutrient important in bone health and immune function. You can receive adequate vitamin D through your diet, generally from eating fortified foods such as dairy products, or through sun exposure, in which UVB rays convert a preliminary form of vitamin D to the active form. Sunscreen blocks the formation of vitamin D by the skin, leading to a potential deficiency if your dietary intake is insufficient. In the December 2007 issue of “The Age,” Dr. Terry Diamond attributes the widespread use of sunscreen to an increased incidence of vitamin D deficiency in Australia. He recommends occasional modest sun exposure without sunscreen in order to maintain healthy levels of vitamin D in your body.