How Sunscreen Affects Vitamin D Levels

Most of the vitamin D we need is produced endogenously in the skin after exposure to ultraviolet B radiation, which is obtained through sunlight. Since vitamin D is important for health, concerns have been raised about sunscreen interfering with vitamin D production. It has been known that clothing and sunscreens that prevent UV radiation from reaching the skin will inhibit the cutaneous synthesis of vitamin D. However, recent studies have shown that circulating vitamin D levels are not significantly affected by practical sunscreen use. This article discusses the evidence for how sunscreens may affect circulating vitamin D levels and describes options for vitamin D supplementation.