Vitamin D3 in psoriasis and related health complications (SQ-138)
Psoriasis is an inflammatory skin condition, where one develops thick, scaly red patches on the skin. It is an autoimmune condition, where skin cells are produced faster than usual.
These patches can be itchy and may cause burning or irritation. While psoriasis is not a life-threatening condition, severe form of psoriasis impact your quality of life both physically and psychologically. Psoriasis can not be cured but it can be managed with the help of topical ointments and medicines.
It is found that people with psoriasis may have lower than normal levels of vitamin D. But can vitamin D supplements help in this chronic skin condition? In this blog, let’s explore the role of Vitamin D in psoriasis as well as in complications associated with this skin condition.
What is psoriasis?
Psoriasis is a chronic inflammatory skin disorder, where a person develops red, itchy patches on the skin, usually covered in white-silverish scales.
These patches are usually found on the elbows, knees, hands, feet and scalp. It can even appear on palms, eyelids, lips, folds of the skin and nails. Psoriasis can become wide-spread and may even lead to swollen, painful and stiff joints.
Psoriasis symptoms may come and go. Some people may experience periods of flare-ups with the appearance of mild to severe symptoms, whereas for some there could be no symptoms for months and sometimes for years at a time. This is called a period of remission. Winter months can aggravate symptoms in some people.
What causes psoriasis?
Psoriasis is an auto-immune skin condition, where an overactive immune system attacks healthy skin cells, which starts growing faster than the normal speed.
Usually, skin cells are produced in the deepest layers of skin. These cells gradually rise to the outermost surface and eventually die and fall off, making way for new cells to take their place. New skin cells are produced and replaced over a period of 3-4 weeks.
But in psoriasis, production of skin cells takes place at four to five times faster than normal. A process that usually takes 3-4 weeks is now occurring within a few days.
This rapid turnover of skin cells leads to the build-up of cells on the surface of the skin, giving rise to raised, thick, red patches that are scaly in appearance. The patches may also cause burning and itching around the affected areas.
Scientists are not clear as to what exactly causes psoriasis, but it is believed that both genetics and environmental factors may play a role in causing the immune system to go haywire.
While family history is a huge risk factor, throat infections, stress, skin injuries, sunburn, smoking and certain medications (lithium, high blood pressure medicine and antimalarial medicine) can also cause psoriasis symptoms to appear or worsen. Sudden withdrawal from steroids may also trigger psoriasis.
“Psoriasis is a chronic, autoimmune skin condition that is caused by a dysfunctional immune system.”
Vitamin D in Psoriasis: Can it help?
Studies show that vitamin D deficiency is common in people with psoriasis. Can low levels be a cause here? Experts believe that vitamin D deficiency may not cause psoriasis, but it can aggravate the symptoms.
Vitamin D is produced when skin is exposed to the sunlight and this process may take a hit in the psoriatic skin lesions, contributing to flare-ups or aggravating symptoms.
In addition, psoriasis can lead to low levels of vitamin D in the body. It could be due to people with this skin condition often wearing clothes that restrict sun exposure and interfere with the natural production of vitamin D in the skin. In addition, the use of drugs like glucocorticoids and immunosuppressants, often prescribed for people with psoriasis, meddle with the metabolism of vitamin D.
Emerging evidence points to the benefits of vitamin D in many chronic and autoimmune diseases. Can vitamin D supplements help in psoriasis? Let us look more closely into what happens in psoriasis, where you are only seeing red, crusty patches on the surface of the skin. Many inflammatory changes are taking place within the body due to an erratically behaving immune system.
Psoriasis is an autoimmune disorder
Your immune system defends your body against disease and infections. It recruits various types of immune cells and signalling molecules to detect, fight and destroy germs. In auto-immune disorders, your immune cells mistake healthy cells as foreign invaders and attack them, causing inflammation.
T cells is one of the immune cells that patrol the body to fight and kill the invading micro-organisms. In psoriasis, something over-activates T cells which misfire and begin attacking skin cells by mistake. Factors that can cause T cells to go into hyperdrive is still a mystery.
This over-activity triggers the release of inflammatory chemicals called cytokines, which further attracts and activates other immune cells, causing skin cells (keratinocytes) to multiply faster. This leads to the formation of characteristic skin lesions seen in psoriasis.
Studies that have investigated the role of vitamin D in managing psoriasis have produced mixed results. But some studies do suggest that vitamin D3 supplements may improve disease symptoms.
How may vitamin D help?
- Regulates immunity and controls auto-immune responses.
- Maintains healthy skin barrier
- Works as an anti-inflammatory by regulating the production of inflammatory cytokines
“The benefits of vitamin D in psoriasis could be attributed to its role in controlling autoimmune responses and inflammation in the body.”
Psoriasis related health complications
A dysfunctional immune system triggers inflammation, which can also affect other organs in the body. People with psoriasis are also at an increased risk of developing other health conditions – including metabolic syndrome, type 2 diabetes, cardiovascular disease and obesity.
Psoriasis, being an autoimmune disease, also increases the risk of other autoimmune disorders such as psoriatic arthritis (PsA), rheumatoid arthritis, vitiligo, autoimmune thyroid disease, multiple sclerosis, celiac disease and inflammatory bowel disease.  
In fact, around 30-40 percent of people with psoriasis tend to develop PsA, which affects joints. Studies also show that people with PsA have lower vitamin D levels.
Signs of PsA include pain, stiffness and swelling in the joints, changes in nails and pain in lower back. A swollen finger or toe is also an indication of PsA.
And it looks like, rheumatoid arthritis (RA) is another condition that is strongly linked with psoriasis. If you have psoriasis and suffer from recurring joint pain, consult your doctor for further investigation.
Interestingly, vitamin D deficiency is also considered as a risk factor for development of rheumatoid arthritis (RA), multiple sclerosis (MS), lupus and Crohn’s disease (CD). On the other hand, healthy vitamin D levels may reduce the risk of MS, SLE, CD and even tuberculosis. 
The impact of psoriasis may be felt beyond your physical well-being. It can majorly reduce quality of life. It can have deep psychological repercussions with people developing low self-esteem, anxiety and depression. However, psoriasis is not infectious and can’t be passed from one person to another.
“Psoriasis may increase one’s risk of developing cardiovascular disease, metabolic syndrome and type 2 diabetes. It also heightens one risk of developing many other autoimmune disorders, with psoriatic arthritis, and RA being the most strongly connected with the disease. Incidentally, vitamin D deficiency puts you at an increased risk of all these health conditions.”
Vitamin D in autoimmune disorders
Vitamin D plays an important role in keeping your immune system in line. While it boosts your natural immunity and protects against infections, vitamin D also regulates your adaptive immunity. This helps your body to control unwanted and damaging auto-immune responses.
Studies show that vitamin D may regulate the activation of T cells, immune cells that play an important role on the development of psoriasis. T cells need to come in contact with dendritic cells, another type of immune cells.
A study found that vitamin D stimulates dendritic cells to produce a chemical that prevents T cells coming in contact with dendritic cells, interfering with its activation. 
As we discussed earlier, scientists believe that it is the overactivation of T cells and the resulting cascade of inflammatory chemicals which cause skin cells to proliferate faster than usual, giving rise to scaly patches.
Research suggests that vitamin D supplementation may help “in clearing psoriatic skin lesions and at the same time also decreasing the risk for cardiovascular disease and decreasing disease morbidity and mortality.” 
There is evidence that vitamin D supplements may help in psoriatic arthritis in some cases. In addition, studies show that vitamin D3 supplements may help in several other autoimmune disorders such as thyroid disorders [6-7], celiac disease, and Chron’s disease.
Vitamin D3 supplements also help in heart disease, metabolic syndrome and type 2 diabetes, mostly because of its role in controlling inflammation.    
“Vitamin D3 supplements show some promise in co-morbidities associated with psoriasis. It can be especially helpful in autoimmune disorders owing to its ability to regulate adaptive immunity.”
Vitamin D Deficiency
Little or no sun exposure and use of sunscreen are two main reasons why vitamin D deficiency is so prevalent across the world. Old age, darker skin color, high latitude, obesity and certain medical conditions such as kidney or liver disorder also increase the risk of vitamin D deficiency. While you skin makes vitamin D, it is converted into its active form in the liver and kidneys.
Certain occupations and cultures require clothing that cover you from head to toe, which again interferes in vitamin D synthesis due to restricted sun exposure.
People who take statin drugs are also at risk as these cholesterol lowering drugs block the production of many important compounds including vitamin D3, vitamin K2 and Coq10.
15-20 minutes of sun exposure between 11.00 a.m. to 3.00 p.m. is ideal to make healthy amounts of vitamin D. But when it comes to sun exposure, time of the day, season and latitude are of essence.
You make vitamin D in your skin when it is exposed to UVB rays, which are stronger near the equator. For people living between latitudes 40° North and 40° South of the equator, there is enough UVB rays throughout the year to trigger vitamin D production in the skin. However, if you live at latitudes beyond this range, you do not have access to strong sunlight during most parts of the winters. In fact, even pollution can impact the amount of UVB that reach you.
The most practical tip here is that you are making vitamin D in sunlight when your shadow is shorter than your height.
“Darker skin tone, obesity, kidney and liver dysfunction, living at high latitude, and use of statin drugs increase your risk of developing vitamin D deficiency. One of the most important tips to getting sensible sun exposure is that your skin is producing good amounts vitamin D, when your shadow is shorter than you really are”
Low magnesium levels and Vitamin D deficiency
Magnesium deficiency is another important factor that contributes towards insufficient vitamin D3 levels. This amazing mineral does a lot of things to keep you healthy. For example, you need it for:
- Energy production
- DNA synthesis and repair
- Maintaining calcium levels
- Glutathione synthesis
- Regulating stress hormones
You also need magnesium to use vitamin D properly. Magnesium converts vitamin D into a form that your cells know how to use. Moreover, magnesium activates enzymes that are involved in the processing of vitamin D in the body. In the absence of magnesium, your body will have trouble absorbing and using vitamin D that you are getting from either sunlight or supplements.
You can also say that vitamin D depletes magnesium in the body. It is because your body is using this mineral to metabolize and use vitamin D effectively. So, when you take a high-dose vitamin D3 supplement but have magnesium deficiency, your body would leech the magnesium from its storage sites, such as bones and muscles. This makes you prone to painful muscle cramps, twitching and even irregular heart beat due to sustained muscle contraction.
In case you are taking vitamin D3 supplements but do not see any improvements in your bone and muscle pain, lethargy and other vitamin D deficiency symptoms, magnesium deficiency could be the reason.
“Magnesium deficiency is one of the most important factor that can lead to depleted levels of vitamin D in the body. It is because you need magnesium to absorb and use the sunshine vitamin.”
Health consequences of vitamin D deficiency
Bone pain, muscle weakness and lethargy are some of the common and early symptoms of vitamin D deficiency. As the levels drop further, one may experience symptoms like excessive head sweating, depression, poor immunity, bloating and constipation.
Vitamin D deficiency can cause osteoporosis, and weak and brittle bones that are prone to fracture. Since vitamin D plays a crucial role in maintaining your immunity, aggressive deficiency can increase your risk of upper respiratory infections, allergies, asthma and autoimmune disorders.
Vitamin D3 supplements may or may not help people with psoriasis. But considering people with this chronic condition are likely to have vitamin D deficiency, supplementation will help correct the deficit. In addition, psoriasis also increases the risk of other health disorders, including autoimmune diseases, so vitamin D3 supplements may provide health benefits in these scenarios.
- Furue at al. Autoimmunity and autoimmune co‐morbidities in psoriasis. Immunology. 2018
- Vashist et al. Association of psoriasis with autoimmune disorders: Results of a pilot study. IDOJ. 2020
- Lisa Prussick, BS and Ronald Prussick, MD. New findings suggest a relationship between psoriasis and vitamin D deficiency, but larger details are still unknown. Practical dermatology. 2013.
- Sau et al. 1,25-Dihydroxyvitamin D3 Restrains CD4+ T Cell Priming Ability of CD11c+ Dendritic Cells by Upregulating Expression of CD31. Frontiers in Immunology. 2019
- Lisa Wenyang Fu and Ronald Vender. Systemic Role for Vitamin D in the Treatment of Psoriasis and Metabolic Syndrome. Dermatol Res Pract. 2011
- Mirhosseini et al. Physiological serum 25-hydroxyvitamin D concentrations are associated with improved thyroid function—observations from a community-based program. Endocrine. 2017
- Nettore et al. Sunshine vitamin and thyroid. Rev Endocr Metab Disord. 2017
- Sunil J.Wimalawansa. Vitamin D and cardiovascular diseases: Causality. The Journal of Steroid Biochemistry and Molecular Biology. 2018.
- Wu et al. Vitamin D supplementation and glycemic control in type 2 diabetes patients: A systematic review and meta-analysis. Metabolism. 2017
- Li X et al. The Effect of Vitamin D Supplementation on Glycemic Control in Type 2 Diabetes Patients: A Systematic Review and Meta-Analysis. Nutrients. 2018
- Alkhatatbeh MJ et al. Association between serum 25-hydroxyvitamin D, hemoglobin A1c and fasting blood glucose levels in adults with diabetes mellitus. Biomed Rep. 2018