Vitamin D and Pemphigus - A Critical Connection

Pemphigus and Vitamin D - Why Deficiency Matters

Pemphigus is a rare autoimmune condition that mainly causes blisters on the skin and mucous membranes. Out of all skin diseases, pemphigus vulgaris and pemphigus foliaceous are the kinds most likely to be seen. The body's immune system attacks desmogleins, causing painful blisters and erosions.

Even though an autoimmune disorder primarily causes pemphigus, vitamin deficiencies directly impact the disease’s severity, progression, and healing duration. Among all the vitamins, low levels of vitamin D show a strong link to pemphigus.

Role of Vitamin D in Immunity

Vitamin D is stored in the body and plays a major role in strengthening immune function. It works on both the human body’s natural and acquired protection against diseases. Additionally, it enhances the ability of monocytes and macrophages to fight infections and helps reduce inflammation.

This vitamin regulates T-cell development, decreasing the function of Th1 and Th17 cells. These two cells play a crucial role in the development of this disease. Th17 cells promote skin damage and inflammation, while Th1 cells contribute to pro-inflammatory responses.

Association Between Vitamin D Deficiency and Pemphigus

The presence of vitamin D in the body is related to changes in the autoantibody production process. Pemphigus causes lesions on the skin by having autoantibodies target desmoglein-1 and desmoglein-3, resulting in detachment of the skin’s cells. Therefore, not having enough vitamin D may weaken the body’s immune system, making the autoantibody activity worse.

Mechanism Linking Vitamin D to Pemphigus

Vitamin D binds to specific Vitamin D Receptors (VDR) found in skin cells (keratinocytes) and the immune system. These regulate gene expression and encourage the growth of skin cells. Hence, if vitamin D is too low in pemphigus patients, their skin may not support healthy structure, and blistering could become worse. Additionally, vitamin D promotes the activity of Tregs, which helps reduce immune system overactivity and lower levels of IL-17 and TNF-α, both of which increase in pemphigus patients.

The other contributing nutritional deficiencies in pemphigus are the following:

• Vitamin B12 and Folate: Patients diagnosed with chronic pemphigus can face vitamin B12 and folate deficiency. Dietary changes, malabsorption, or corticosteroid side effects cause this condition. If you do not have sufficient vitamins, you may develop anaemia and mouth sores, which can exacerbate the pemphigus condition.
• Zinc: Even though zinc is not a vitamin, it has been observed to be deficient in individuals with autoimmune skin diseases. Zinc deficiency can disrupt the body's ability to regulate inflammation, assist wound healing and tune the immune response. Therefore, low zinc levels delay skin recovery and wound healing in patients with pemphigus.

Vitamin D Supplementation in Pemphigus Management

Most dermatologists recommend taking vitamin D supplementation in a measured dosage depending on their baseline serum levels. Furthermore, the patient’s condition and their reaction to the product should be regularly checked.

Taking vitamin D supplements should depend on someone’s initial blood levels. Physicians suggest taking 50 nmol/L (20 ng/mL) of this vitamin supplement for improving autoimmune diseases. However, levels above 125 nmol/L (50 ng/mL) can be too high. Healthcare providers should monitor patients taking steroids for a long time for changes in their vitamin D and calcium levels to prevent problems like toxicity.

Having low levels of vitamin D is the most significant vitamin issue in people with pemphigus. Thus, it may increase autoimmune reactions, reduce the body’s ability to heal skin wounds and help keep the disease active. Hence, carers should provide appropriate nutritional support and carefully monitor patients to avoid the side effects of medication used to treat this condition.