Analysis of Response of Subjects With Atopic Dermatitis or Psoriasis to Oral Vitamin D3

Atopic Dermatitis (AD) is a chronic inflammatory skin disorder in which the skin becomes extremely itchy and is susceptible to recurrent skin infections. AD is thought to occur from a combination of immunological, genetic, and environmental factors. Individuals with AD are at risk for developing a severe and widely disseminated infection called eczema vaccinatum (EV). EV is caused when the live attenuated vaccinia virus in the vaccine reproduces and spreads throughout the body. Individuals with AD lack certain antimicrobial peptides, specifically cathelicidins. This trial also includes a sub-study with individuals who have psoriasis. Psoriasis is also an immune-mediated skin disease, and is characterized by scaling skin and inflammation (pain, swelling, heat, and redness). Most psoriasis cause patches of thick, red skin with silvery scales. These patches can itch or feel sore. This sub-study will provide additional information on psoriatic responses to oral vitamin D. (Originally listed separately as ADVN-CATH-03-01).