Vitamin D and Psoriasis

Psoriasis is a condition that affects the skin, leaving lesions or scaly patches that are raised and red in color. Medically, it is an autoimmune disorder, as the immune system causes too many skin cells to be produced. There is reason to believe that there is a strong link between psoriasis and vitamin D deficiency, which is why many treatment options focus on raising levels of vitamin D. However, what vitamin D can do is to improve the condition. It does not heal it or even prevent it.

What Is Psoriasis?

Essentially, it is an autoimmune disorder that causes crusty, flaky, red patches of skin to appear, which are covered in silvery scales. These tend to appear on the knees, elbows, lower back and scalp. However, they can exist anywhere on the body. Most people only have small patches, but even these can become sore and itchy. The condition affects around 2% of the population and, while being most common in adults younger than 35, it can happen at any age. Men and women are equally affected by it. Psoriasis can exist in various degrees of severity, with some suffering a minor irritation and others seeing a significant reduction in their quality of life. It is a chronic disorder, characterized by frequent flare-ups during which time the symptoms tend to become worse.

Why Does Psoriasis Happen?

Psoriasis, at its heart, is an overproduction of skin cells. Usually, every three to four weeks, our body replaces dead skin cells. With people who have psoriasis, cells are replaced every three to seven days. As a result, skin cells build up and this creates patches. The medical community still doesn’t not fully understand why these patches appear, although it is clear that it is caused in part by the immune system. The immune system is supposed to defend the body against infections and diseases. The immune system of people with psoriasis consider the skin cells to be something that it must fight against.

The exact causes of psoriasis are also poorly understood. However, there is now some agreement that genetic factors play a vital role. Additionally, most people suffer from ‘triggers’, which cause the symptoms to flare up. Possible triggers include throat infections, skin injuries and a number of medications. Fortunately, psoriasis is not contagious.

How to Diagnose and Treat Psoriasis

Usually, psoriasis first appears when someone is between 15 and 25 years old. They start to experience patches on the soles of their feet, the palms of their hands, their genitals, their scalp, their knees, their elbows and in other places. In very severe cases, the entire body can be covered with itchy, painful patches.

Psoriasis patches are present in 90% of people who suffer from it. There is also a pustular form of psoriasis, whereby people experience raised, pus-filled bumps, which are free from bacteria. The patches in regular psoriasis are called ‘psoriatic plaques’ and they are most common in areas where a skin injury has taken place.

Psoriasis tends to go through stages, with frequent remissions and reoccurrences. Because of this, it is very hard to determine whether or not treatment works. Three grades of psoriasis exist, as shown in the table below.

Grade Characteristics
Mild Patches are found on less than 3% of the patient’s body.
Moderate Patches are found on between 3% and 10% of the patient’s body.
Severe Patches are found on more than 10% of the patient’s body.

It is unclear what causes psoriasis, other than it is related to the immune system. This is because cytokines and T cells are involved, as well as a number of local skin characteristics. Essentially, the growth and division of skin cells is out of control. While genes do play a part in this, they are not the exclusive cause of the illness.

Those who suffer from psoriasis often have a diminished quality of life. Depression is also common among patients. This is also due to the fact that around 15% develop psoriatic arthritis, meaning they suffer from swelling, stiffness and pain in the joints. Like the skin condition, this comes and goes and has mild pain. However, it can be progressive in nature, and it can result in deformities as well. This is most common in the toes and fingers.

Treatment for psoriasis exists in numerous forms. The most common ones include:

• Medication to reduce T cells
• Medication to eliminate cytokines
• Topical steroid cream treatment
• Phototherapy, in which someone is exposure to UV irradiation
• Drugs like cyclosporine or methotrexate, which suppress the immune system
• Dexamethadone or other oral steroid drugs
• Antihistamines, which help to reduce itching

Unfortunately, psoriasis is a chronic illness, which means sufferers have it for life. Most people, however, only have a few, localized outbreaks. Others are less fortunate and have frequently occurring, severe outbreaks.

Psoriasis and Vitamin D Deficiency

In June 2011, new guidelines were released by the Endocrine Society. They stated that vitamin D deficiency is now common in all population groups and supplementation should be considered. Interestingly, people who suffer from psoriasis frequently have low levels of vitamin D. The medical society agrees that this is not the cause of psoriasis, but that it does play a part. At the same time, however, studies were completed at Silpoint Centre, British Columbia, and they found that there is no association between autoimmune diseases’ markers characteristics and vitamin D deficiency. In fact, they even found that some of the participants had elevated vitamin D3 levels. This led them to theorize that people with autoimmune diseases may have problems with their vitamin D receptors, rather than with the intake of the vitamin itself.

What is known, however, is that vitamin D plays an important role in the treatment of psoriasis. There is an element of adaptive immunity to psoriasis (through the T cells) and vitamin D is known to reduce adaptive immunity. In layman’s terms, this means that vitamin D can reduce cell proliferation, something it does in cancers as well. It can also help to slow down the production of new skin cells.

Scientists now agree that vitamin D can play an important role in treating and managing psoriasis, in the following ways:

• Sun exposure, whereby the skin can synthesize vitamin D, leading to shorter and less severe attacks of psoriasis.
• Heliotherapy (sunlight therapy) kills any T cells in the skin that have been activated. As a result, turnover is reduced to levels closer to average people, helping the inflammation and scaling to subside. Only brief exposure is required, with a few minutes per day being sufficient. It is vital to not opt for prolonged exposure, as this can damage the skin and thereby make symptoms worse.
• UVB phototherapy, such as narrowband and broadband excimer laser, use artificial light sources to provide a controlled dose of UVB radiation. It is quite commonly used to treat psoriasis patches, particularly where topical treatment is ineffective. Treatment has to be monitored properly so that the patient does not get burned, which is possible with this type of light.
• UVB light therapy has been very successful in treating sensitive to light skin when combined with topical treatments.
• Topical preparations with vitamin D, such as tacalcitol or calcipotriene, have been shown to be very effective in treating moderate and mild psoriasis. This is because these topical treatments slow down the production of new cells, while at the same time being anti-inflammatory. Additionally, these types of medication make it easier for other topical treatments, including topical steroids such as corticosteroids, to be more effective.

Light Therapy

Many people who suffer from psoriasis are prescribed light therapy. This is because UVB light exposure helps to relieve redness, as well as healing lesions. UVB radiation is what your body needs in order to manufacture vitamin D. Studies took place at Dublin’s St. Vincent’s University Hospital in 2008 and 2009, looking at 60 people suffering from psoriasis. They found that those who received light therapy three times per week resolved their symptoms and doubled their levels of vitamin D. However, doctors concluded that the raised levels of vitamin D were not the reason why symptoms subsided. Rather, it was because of the light itself.

You don’t have to go to a doctor to receive light therapy. Simply standing out in the sun is enough. However, it is very important to not have too much exposure, leading to sunburns, because this can make the situation worse. Because the link is with sunlight and not vitamin D, psoriasis symptoms will not improve simply by taking oral vitamin D. This is because taking the vitamin orally will not prompt the body to produce more calcitriol, as it does through sun exposure.

Topical Vitamin D Treatment

Calcipotriene is one of the most commonly used forms of topical vitamin D in the treatment of psoriasis, and it has had some excellent results. A study was conducted in November 2002 and published in ‘Cutis’. The research was completed by the University of California’s Department of Dermatology’s researcher J. Koo, who found that treating scalp psoriasis with calcipotriene was very effective. This was particularly true if other traditional steroid treatments were also employed. It was found that those who used vitamin D cream could reduce the amount of other steroids that they had to use. This study has been replicated with similar results with different steroid drugs and combination drugs by a number of research facilities.

Some Considerations

It is very important to eat a balanced, healthy diet to maintain adequate vitamin D levels. Choosing fortified products and increasing the amount of oil fish you eat can have a tremendous impact on your overall health, whether you suffer from psoriasis or not. If you feel you have a deficiency, you can request a blood test through your doctor. If levels are found to be low, supplementation may be required. However, it is important to not take supplements unless prescribed by your doctor because vitamin D can be toxic if taken in too high levels.

Resources and References:

How Vitamin D Can Help Psoriasis – Effects of vitamin D on psoriasis. (National Psoriasis Foundation)
Vitamin D Status in Patients with Chronic Plaque Psoriasis – Vitamin D levels in patients with chronic plaque psoriasis. (
A Pilot Study Assessing the Effect of Prolonged Administration of High Daily Doses of Vitamin D on the Clinical Course of Vitiligo and Psoriasis – Treating vitiligo and psoriasis with vitamin D. (
Superior Efficacy of Calcipotriene and Betamethasone Dipropionate Aerosol Foam Versus Ointment in Patients with Psoriasis Vulgaris – Study on treatment for psoriasis vulgaris. (
Combination of Calcipotriene (Dovonex) Ointment and Tazarotene (Tazorac) Gel Versus Clobetasol Ointment in the Treatment of Plaque Psoriasis: A Pilot Study – Study on treatment of plaque psoriasis. (