Slide show: 5 ways to thrive with psoriasis through the holidays

Holiday decorations and sparkle can't conceal a key, missing source of light during the winter: the sun. Limited exposure to sunlight reduces your body's level of vitamin D, which may, in turn, weaken your immune system's ability to repair your skin. Researchers have found that people with plaque psoriasis often have lower than normal levels of vitamin D, a problem that worsens during winter months.

Good dietary sources to boost vitamin D include fortified foods, such as milk and yogurt, and fatty fish, such as salmon, trout, tuna and halibut. Relying on your diet for vitamin D may not be enough, however, if you're living with psoriasis. Treatment options to increase your vitamin D levels include light therapy (phototherapy), which exposes your skin to natural or artificial ultraviolet light, as well as topical creams or solutions that contain synthetic vitamin D. Dietary supplements also may offer benefit. Ask your doctor whether adding vitamin D therapy to your treatment plan in the winter could help reduce your risk of skin flares.