Vitamin D Status, Disease Specific and Quality of Life Outcomes in Patients With Cutaneous Lupus

Lupus is a disease in which the immune system, which normally fights infection, begins to attack healthy cells in the body. This phenomenon is called autoimmunity and what the immune system attacks is called the autoantigen. Lupus can affect many parts of the body and often affects the skin, with immune cells attacking autoantigens in the skin and causing a rash. This rash is often visible to the public because it tends to occur on sun-exposed areas, for example a patient's face, chest, and arms. For this reason, among others, skin lupus can be a source of disability and poor health related quality of life in many patients with this disease. It is not completely understood why or how someone might develop lupus, however there are likely many reasons which include their genetics and also the kind of environment they live in.

One such environmental factor, vitamin D, is more commonly known as a vitamin important for bone health. However, we are learning that vitamin D has effects all over the body, and is also important for a healthy immune system. Low levels of vitamin D have been associated with an increased risk of other autoimmune disorders such as diabetes and multiple sclerosis, and have also been found to be common in skin lupus patients.

Vitamin D is made in the skin when it is exposed to the sun, specifically ultraviolet B radiation (UVB). The main source of vitamin D for most people is its production in the skin because the normal American diet is not high in vitamin D. However, patients with skin lupus tend to stay out of the sun because their rash is made worse by sunlight, which is thought to produce more of the autoantigens in the skin attacked by the immune system. Additionally, as skin doctors (dermatologists) we recommend sun protection to skin lupus patients to minimize sun-sensitivity and prevent flares of their skin disease. However we may be putting them at risk for low vitamin D status and even more severe disease. Another risk factor that puts skin lupus patients at risk for vitamin D deficiency is that these patients generally have darker skin types which blocks UVB and further limits vitamin D production in the skin.

Given that skin lupus patients are at high risk for low vitamin D status as mentioned above, the investigators propose a research study that will provide information about vitamin D levels in these patients. The investigators seek to identify how many skin lupus patients have low vitamin D status and how vitamin D influences the natural history of this skin disease. Additionally the investigators will evaluate whether or not supplementation with high dose vitamin D will lessen the severity and negative quality of life impact of skin lupus. Supplementation of vitamin D by mouth is an inexpensive, well tolerated, and safe over the counter method to replete and maintain a normal vitamin D status. Studies in other autoimmune diseases, specifically Crohn's disease and multiple sclerosis, have shown that high dose vitamin D supplementation improves disease severity. It is the hope of the investigators that this will also be observed in skin lupus patients.

In summary, the investigators seek to move beyond establishing an association between vitamin D status and skin lupus. The investigators aim to elucidate the therapeutic benefit, if any, of vitamin D status on disease severity and quality of life while controlling for important factors that may influence vitamin D status. If the investigators are to show improvement in disease severity with vitamin D supplementation, this would be a cost-effective additional therapy to our standard clinical practice. Future research would also allow us to investigate other alternative markers of vitamin D deficiency and disease activity in skin lupus patients, a population at high risk for low vitamin D status and in need of further research.