Psoriatic Arthritis: Integrative Treatment, Vitamin D and Lifelong Care

Does vitamin D help psoriatic arthritis? What the research shows

People with psoriatic arthritis have lower vitamin D levels than healthy people, according to a 2023 meta-analysis in Seminars in Arthritis and Rheumatism [3]. A review of randomised trials in Nutrients found none that tested vitamin D supplements in psoriatic arthritis itself [5], and we found none since in PubMed (October 2026). The US National Psoriasis Foundation’s 2018 diet recommendations weakly recommend vitamin D supplements for people with psoriatic arthritis, alongside standard medical treatment [6].

• Lower levels: in the 2023 meta-analysis, people with psoriatic arthritis had lower vitamin D (25-hydroxyvitamin D) than healthy controls, though slightly higher than people with psoriasis of the skin alone; the authors call for more studies on its role in causing and treating the disease [3].
• No trial in psoriatic arthritis yet: a 2021 review of randomised trials of vitamins in inflammatory rheumatic diseases found none in psoriatic arthritis; it advises giving vitamin D to people who are deficient, to prevent bone, joint and muscle problems [5].
• Psoriasis of the skin: vitamin D creams, lotions and ointments are one of the main treatments for psoriasis, according to the NHS [7]; for vitamin D tablets, a meta-analysis of randomised trials could not confirm a benefit for psoriasis [8].
• Prevention: in the VITAL trial of 25,871 older adults in the US (men aged 50 and over, women 55 and over), 2,000 IU of vitamin D a day for about 5 years led to 22% fewer confirmed new autoimmune diseases overall than placebo [9]. It tested prevention, not treatment, and psoriatic arthritis was not reported on its own.
• Higher doses under supervision: in a small 2013 pilot study without a comparison group, run by the Brazilian group that developed the protocol, 9 people with psoriasis given high daily doses of vitamin D for 6 months under medical monitoring all improved on the psoriasis severity score, and calcium and kidney tests stayed normal [10]. This is the approach used in supervised vitamin D therapy (Coimbra Protocol). It has not yet been tested in a controlled trial in psoriatic arthritis.
• Where guidance differs: vitamin D therapy is not among the treatments in the 2023 EULAR recommendations for psoriatic arthritis [11], and the usual recommended intake for adults is 600 to 800 IU a day, according to the US National Institutes of Health [12].
• What this means for you: check your vitamin D together with PTH (parathyroid hormone), calcium and kidney function, and never start high doses on your own.

Weight and psoriatic arthritis: the risk factor you can change

Extra weight is the clearest risk factor you can change. In people with psoriasis, obesity is linked with about a 75% higher risk of psoriatic arthritis, and the risk rises about 6% for each point of BMI. This comes from a 2021 meta-analysis of 16 studies of 322,967 people in the Journal of the American Academy of Dermatology [4].

• Weight loss and the joints: in a Swedish study of 41 people with psoriatic arthritis and obesity, without a comparison group, a medically supervised very-low-energy diet led to a median loss of about 19% of body weight. The share with minimal disease activity rose from 29% to 54%, with less joint, tendon and skin disease, and more weight lost went with more improvement [13].
• With medicines: in 126 overweight people starting TNF-blocker medicines, those who lost at least 5% of their weight had about 4 times higher odds of reaching minimal disease activity [14].
• Other linked factors: in the same meta-analysis, a past injury to a joint or bone and a fracture were also linked with developing psoriatic arthritis [4].
• What this means for you: a healthy, steady weight through diet and movement is part of every plan we make, as the 2021 EULAR lifestyle recommendations and the US National Psoriasis Foundation advise [15][6].

What is psoriatic arthritis?

Psoriatic arthritis is an immune-mediated inflammatory disease of the joints and the entheses (where tendons and ligaments attach to bone), according to the US National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) [1].

• Who gets it: adults most often, men and women equally; most people already have psoriasis, and on average the arthritis starts about 7 to 10 years after the skin [1].
• How common: about 1 in 5 people with psoriasis, and about 1 in 4 in studies that used the CASPAR classification criteria [2].
• Joints before skin: a small group of people get joint pain before the skin rash [1].
• Causes: genes and family history, with triggers such as obesity, infection, injury or stress [1].

What are the symptoms of psoriatic arthritis?

The main symptoms are pain, swelling and stiffness in one or more joints, swollen fingers or toes, nail changes and tiredness, according to the NHS [16].

• Fingers and toes: a painful, sausage-like swelling of a whole finger or toe (dactylitis) [1].
• Heels and feet: tenderness where tendons attach to bone, often at the back of the heel or the sole of the foot [1].
• Nails: tiny dents (pitting), crumbling, colour change or the nail lifting from the nail bed [16][1].
• Back and neck: stiffness in the neck, lower back and hips when the spine is affected [1].
• Morning stiffness: symptoms are often worse first thing in the morning and improve with movement [16].
• Eyes and gut: some people get eye inflammation (uveitis) or inflammatory bowel disease [1].
• Heart and metabolism: people with inflammatory arthritis have a higher risk of heart disease, and this may also apply to psoriatic arthritis, according to EULAR, which makes the rheumatologist responsible for managing this risk [17].

Psoriatic arthritis vs rheumatoid arthritis, osteoarthritis or gout: what is the difference?

Psoriatic arthritis often affects joints unevenly and can swell a whole finger or toe, change the nails and cause heel or tendon pain, usually with psoriasis in you or your family and a negative rheumatoid factor, according to the CASPAR classification criteria [18][1]. Rheumatoid arthritis usually affects the same small hand joints on both sides. Osteoarthritis, rheumatoid arthritis and gout can all cause similar joint pain, so the NHS advises a doctor’s check [16].

Why early diagnosis matters: the 6-month window

Even a 6-month delay before seeing a specialist can matter. In an Irish study of 283 people with psoriatic arthritis, those first seen more than 6 months after their symptoms began were more likely to have joint erosions and worse long-term physical function (Annals of the Rheumatic Diseases, 2015) [19].

• Only 3 in 10 early: in that study, only 30% were seen by a rheumatologist within 6 months of their first symptoms [19].
• How it is diagnosed: an examination, blood tests, X-rays, ultrasound or MRI scans and sometimes a joint fluid test, according to the NHS [16]; doctors often use the CASPAR classification criteria as a guide, which combine psoriasis (now, in the past or in the family), nail changes, swollen fingers or toes, a negative rheumatoid factor and typical X-ray changes [18].
• What to do: if you have psoriasis and joint pain, stiffness or swelling that keeps coming back, see a doctor; the NHS advises this even if you do not have psoriasis [16].

How does Cure4Pain treat psoriatic arthritis?

Cure4Pain, an integrative and functional medicine clinic in Mumbai with online consultations worldwide, manages psoriatic arthritis over the long term with supervised vitamin D therapy (Coimbra Protocol), nutritional cofactors, gut support, thyroid and infection checks, weight care and resistance exercise. Care starts after a full blood panel, is coordinated with your existing consulting physician, and every plan is reviewed by Dr Krushal Pabari and AT. Chintan Dalal. Psoriasis and psoriatic arthritis are a main focus of our practice:

1. A full autoimmune blood panel first: before the first consultation (see the next section), so the plan is based on your own results.
2. Supervised vitamin D therapy (Coimbra Protocol): daily therapeutic doses of vitamin D, used for its role in regulating the immune system, not as casual supplementation, with a calcium-restricted diet and regular blood tests.
3. Cofactors: magnesium matched to the vitamin D dose (clinic practice, not tested in a trial), trace minerals, a methylated B complex and algae-based omega-3 (EPA and DHA).
4. Gut support: digestive enzymes or digestive support, and bile support.
5. Underlying problems: we look for an underactive thyroid (clinical or subclinical) and for infections, which NIAMS lists among possible triggers [1].
6. Weight and movement: a healthy diet for steady weight loss when needed, and resistance training or water exercise (see below).
7. Ongoing review: blood tests and symptoms are reviewed regularly, and the plan is adjusted over time.

Clinic observation: in our clinic, people diagnosed early have often reached well-controlled joints and skin within about 9 to 12 months, and people with severe psoriatic arthritis for 5 years or more have often needed 2 to 2.5 years. This is an observation from our practice, not a trial result: psoriatic arthritis naturally comes and goes, many of our patients also take standard medicines, individual results vary, and further studies are needed. Some patients have had flares after missing or suddenly stopping vitamin D and cofactor therapy; psoriatic arthritis also flares on its own, so we cannot say the two are linked, and any change to your plan is made with you, under clinical guidance from Team Cure4Pain.

What published studies show: vitamin D is low in psoriatic arthritis [3]; weight loss improves disease activity [13]; resistance training improves function [20]; as of October 2026, we found no controlled trial of supervised vitamin D therapy (Coimbra Protocol), digestive enzymes or bile support in psoriatic arthritis.

If you take medicines for psoriatic arthritis, they continue as per guidelines: Dr Krushal Pabari prescribes and adjusts them under clinical guidance from Team Cure4Pain, in coordination with your existing consulting physician.

Our autoimmune blood panel: what we test before the first consultation

Every person with psoriatic arthritis, and every other autoimmune patient, completes a full autoimmune blood panel (about 100 measures) before the first consultation, so that we see the whole picture:

• Vitamin D status and PTH (intact parathyroid hormone), read together
• Vitamin B12
• Lipid profile (cholesterol and triglycerides)
• Complete blood count with differentials and iron studies
• Kidney function and liver function
• ANA (antinuclear antibodies) by the IFA method
• hsCRP (a sensitive marker of inflammation)
• Fasting insulin and HbA1c (blood sugar over about 3 months)
• Thyroid profile

“About 100 measures” means the individual results across these groups. These tests do not diagnose psoriatic arthritis; they show your vitamin D and PTH balance, inflammation, blood sugar, cholesterol, thyroid, kidney and liver health before any therapy starts. Lipids, fasting insulin and HbA1c matter because inflammatory arthritis is linked with a higher risk of heart disease [17]. Your rheumatologist may also check rheumatoid factor, anti-CCP antibodies, HLA-B27 or uric acid to tell psoriatic arthritis apart from other types of arthritis. In India, the panel is available at a lower cost through our patient portal, with home collection across India. Outside India, the tests are done at a laboratory near you and reviewed with you in the consultation.

Supervised vitamin D therapy (Coimbra Protocol) for psoriatic arthritis: what it is and how it is kept safe

Supervised vitamin D therapy (Coimbra Protocol) is a high-dose vitamin D approach for autoimmune diseases that comes from the group of Dr Cicero Coimbra in Brazil. Daily doses far above the usual supplement range are adjusted to each person’s PTH and calcium levels, with a calcium-restricted diet, at least 2.5 litres of fluid a day and regular blood tests, as described in a 2022 safety study in Nutrients [21]. See our Coimbra Protocol page.

• The safety limit: according to the US National Institutes of Health, the upper limit for adults without medical supervision is 4,000 IU a day, and too much vitamin D can raise blood calcium, which can harm the kidneys and heart [12]. Doses in supervised vitamin D therapy (Coimbra Protocol) are well above this limit, which is why it is given only under medical supervision with regular blood tests.
• Safety data: in a 2022 study in Nutrients of 319 people with autoimmune diseases given this therapy under experienced physicians for up to 3.5 years, average calcium and kidney results stayed in the normal range. The data came from a single German centre that provides the therapy, without a comparison group [21].
• The cautious view: a 2020 review in Nutrients notes that the long-term safety of high-dose vitamin D is not well studied and that toxicity can cause kidney failure and heart rhythm problems, so such therapy needs physician supervision [22].
• Effect: the only published study in psoriasis is the 2013 pilot of 9 people without a comparison group [10]; we found no trial in psoriatic arthritis, so further studies are needed.
• Why magnesium: the enzymes that activate vitamin D in the liver and kidneys need magnesium, according to a 2018 review in the Journal of the American Osteopathic Association [23]. We match magnesium to the vitamin D dose; this matching is clinic practice and has not been tested in a trial.
• Never on your own: please do not copy doses from the internet or from videos; the dose is personal and changes over time.

Do omega-3, magnesium or gut health matter in psoriatic arthritis?

Single foods and supplements have only small effects in arthritis, according to the 2021 EULAR review of diet in rheumatic and musculoskeletal diseases, so we use them as part of a whole plan, not alone [24].

• Omega-3: omega-3 reduced painkiller use but did not clearly improve disease activity. In a Danish placebo-controlled trial of 145 people with psoriatic arthritis, fish oil for 24 weeks reduced the need for NSAIDs and paracetamol, but the change in disease activity was not significantly greater than placebo [25]. In our practice we use algae-based omega-3 (EPA and DHA); we found no trial of algae-based omega-3 in psoriatic arthritis.
• Magnesium: most of the body’s magnesium is inside cells and bone, and blood magnesium does not show how much the body holds, according to the US National Institutes of Health [26]; we assess magnesium from the overall clinical picture and give it as elemental magnesium (absorption varies by form). We found no trial of magnesium in psoriatic arthritis.
• B vitamins: a meta-analysis found lower folate and higher homocysteine in psoriasis, but no difference in vitamin B12 [27]; folic acid is also advised for people taking methotrexate, to prevent its side effects [5].
• Gut bacteria: gut bacteria are less varied in people with psoriatic arthritis than in healthy people, a pattern similar to inflammatory bowel disease, according to a small 2015 study in Arthritis & Rheumatology [28].
• Silent gut inflammation: some people with spondyloarthritis, the family of conditions psoriatic arthritis belongs to, have gut inflammation without gut symptoms, and researchers think it may take part in the disease [29].
• Digestive and bile support: part of our clinic practice for gut health; we found no trial of them in psoriatic arthritis.

Thyroid problems and hidden infections: why we look for them

Thyroid problems are more common in psoriatic arthritis: in an Italian study in The Journal of Rheumatology, thyroid autoimmunity was more common in men and women with psoriatic arthritis, and subclinical hypothyroidism in women, than in the general population, and the authors advise thyroid tests as part of the assessment [30].

• Over time: a follow-up study found more new cases of hypothyroidism and thyroid antibodies in people with psoriatic arthritis, especially women, than in matched controls [31].
• Infections: NIAMS lists infection among the possible triggers of psoriatic arthritis [1], but a 2018 systematic review found the studies inconsistent, with throat and streptococcal infections the most worth studying [32].
• Teeth and gums: gum disease (periodontitis) is now recognised as linked with psoriasis and psoriatic arthritis, and may play a part in their development or flares [33].
• Viruses: the strongest evidence that a virus can trigger an autoimmune disease is Epstein-Barr virus in multiple sclerosis [34]; for psoriatic arthritis this has not been shown.
• In our clinic: when disease activity stays high, we sometimes look for dental, post-viral (for example Epstein-Barr virus), parasitic or fungal infections, which blood tests do not always show at first. Where one is found, it is treated as part of your plan, with gut support protocols, or you are referred. This is clinic practice, not a proven method; it is not known whether treating such infections changes psoriatic arthritis, and further studies are needed.

Exercise for psoriatic arthritis: resistance training and water exercise

Resistance training helps. In a Brazilian randomised trial of 41 people with psoriatic arthritis, resistance exercise twice a week for 12 weeks improved physical function, disease activity and quality of life compared with medicines alone (Clinical Rheumatology, 2018) [20].

• A second trial: functional training and resistance exercise were similarly effective for function, disease activity and strength in psoriatic arthritis [35].
• Water exercise: the NHS recommends low-impact exercise such as swimming and walking [16]; in ankylosing spondylitis, a related condition, a meta-analysis of 8 studies found water therapy reduced disease activity and pain [36]. We found no water-exercise trial in psoriatic arthritis itself.
• What we advise: resistance training as the core strengthening exercise, with moderate loads increased gradually, and swimming or walking in a pool; no sudden jerky movements, excessive gym work or heavy weights.
• Keep active: the 2025 EULAR recommendations advise physical activity as standard care for people with inflammatory arthritis, adapted to each person [37].

What is the best diet for psoriatic arthritis?

There is no single psoriatic arthritis diet: the 2021 EULAR lifestyle recommendations advise a healthy, balanced diet and a healthy weight [15], and the US National Psoriasis Foundation strongly recommends a lower-calorie diet for weight loss in people who are overweight [6].

• Weight first: steady weight loss when you are overweight is the dietary step with the clearest evidence in psoriatic arthritis [13][14].
• Single foods: effects of single foods or supplements are small [24].
• Gluten: a gluten-free diet is advised only for people whose blood tests show gluten sensitivity, according to the National Psoriasis Foundation [6].
• Alcohol and herbal remedies: the NHS advises cutting down on alcohol if you take medicines, and not using herbal remedies because they may interfere with your medicines [16].
• On supervised vitamin D therapy (Coimbra Protocol): dairy and other high-calcium foods are limited and water intake is kept high, as explained on our Coimbra Protocol page.
• Smoking: smoking can make psoriatic arthritis symptoms worse, according to the NHS, and smokers should be supported to quit, according to EULAR [16][15].

What is the conventional treatment for psoriatic arthritis? Medicines as per guidelines

Medicines are the standard treatment for psoriatic arthritis, according to the 2023 EULAR recommendations and the 2021 GRAPPA recommendations [11][42]:

• Symptom relief: NSAIDs (anti-inflammatory painkillers), used alone only in mild disease and for a short time; steroid injections into a joint may be added; steroid tablets are not recommended, according to EULAR [11].
• Swollen joints: a conventional DMARD (disease-modifying anti-rheumatic drug) started early, with methotrexate preferred; sulfasalazine and leflunomide are alternatives, according to EULAR [11].
• If the target is not reached: a biological medicine that blocks TNF, IL-17, IL-23 or IL-12/23; skin psoriasis, spine or heel involvement, eye inflammation (uveitis) and bowel disease guide the choice, according to EULAR and GRAPPA [11][42].
• JAK inhibitors: mainly after a biological medicine has not worked, weighing heart, blood clot and cancer risks; apremilast suits mild disease when these are unsuitable, according to EULAR [11].
• Safety checks: the Asia-Pacific (APLAR) 2025 recommendations, which include India, cover tuberculosis and hepatitis B screening before these medicines [43].
• DMARDs take time: they can take several months to work, so the NHS advises continuing them even if you do not feel better straight away [16].
• Treatment target: the 2023 EULAR recommendations aim for remission (the guideline term for no signs of active disease on a standard score, with treatment continued) or, if that is not possible, low disease activity [11].

At Cure4Pain, Dr Krushal Pabari prescribes and adjusts these medicines as per guidelines, under clinical guidance from Team Cure4Pain, in coordination with your existing consulting physician, alongside the integrative plan; never stop or change them on your own.

Do acupuncture or dry needling help psoriatic arthritis? Why we rarely use them

As of October 2026, we found no controlled trial of acupuncture or dry needling in psoriatic arthritis, and a 2023 systematic review of non-drug treatments for psoriatic arthritis included none [38].

• Skin injury and psoriasis: psoriasis can appear on skin that has been injured (the Koebner phenomenon), including by medical procedures [39], and a psoriasis flare at acupuncture needle sites has been reported [40].
• Inflamed joints: when inflammation is high, we avoid needling the joints.
• In our clinic: acupuncture, dry needling and electroacupuncture are used very rarely, almost never, in psoriatic arthritis; our care rests on supervised vitamin D therapy (Coimbra Protocol), cofactors and exercise.

Can psoriatic arthritis go away? Lifelong management and flares

Psoriatic arthritis is a long-term condition, but treatment can slow its progression, ease pain and protect the joints, according to NIAMS, and early treatment is linked with better outcomes and less damage [1]. The 2023 EULAR recommendations set remission (the guideline term for no signs of active disease on a standard score, with treatment continued), or at least low disease activity, as the treatment target [11].

• Flares: symptoms often come and go in flares [16].
• In our clinic: some patients have had flares after missing, skipping or suddenly stopping vitamin D and cofactor therapy. Psoriatic arthritis also flares on its own, so we cannot say the two are linked, and further studies are needed. The plan is lifelong, and any change is made with you, under clinical guidance from Team Cure4Pain.

When is joint pain urgent?

Get urgent medical help if a joint suddenly becomes very painful, hot, swollen or red, you cannot move it or put weight on it, or you also have a high temperature, according to the NHS, as this can be a joint infection (septic arthritis) [41]. Eye pain, redness or blurred vision can be uveitis, which must be treated promptly to avoid vision loss, according to NIAMS [1].

Does Cure4Pain work with my own doctor for psoriatic arthritis?

Yes. We share our findings with your existing consulting physician, rheumatologist or dermatologist. At Cure4Pain, Dr Krushal Pabari prescribes and adjusts these medicines as per guidelines, under clinical guidance from Team Cure4Pain, in coordination with your existing consulting physician, alongside the integrative plan; never stop or change them on your own.

What happens at a psoriatic arthritis consultation?

After your autoimmune blood panel, your first consultation (in Mumbai or online) covers your history, joints, skin and nails, a review of your tests and scans, and a written plan for supervised vitamin D therapy (Coimbra Protocol), cofactors, diet and exercise. Follow-up blood tests and reviews are planned at regular intervals. Individual results vary.

Evidence: key studies

Who treats you

• Dr Krushal PabariMD, PGCP - Rheumatic & Musculoskeletal Diseases. Assistant Professor, Cooper Hospital; Guest Professor, CMP Homoeopathic Medical College.
• AT. Chintan Dalal, N.D.BNYS, R.AP. Functional nutrition and Coimbra Protocol practitioner.

Consultations look at the whole person: alongside the medical and nutritional plan, we bring a strong interest in behavioural science to counselling on stress, sleep and lasting lifestyle change.

How consultations work: Mumbai or online worldwide

Book through our patient portal. You can see us in person at our clinic in Malad West, Mumbai, or online from anywhere. Your first consultation reviews your history and tests; we then agree a plan together and set the monitoring schedule.

Related conditions and articles

• PsoriasisScaly, inflamed skin patches; vitamin D, nutrition and patient cases.
• Ankylosing SpondylitisInflammatory back pain and stiffness, often with HLA-B27.
• Rheumatoid ArthritisJoint pain and stiffness; integrative care in coordination with your existing consulting physician.
• Osteoarthritis & Joint PainHip, hand and joint pain from osteoarthritis, treated without surgery.
• Lupus (SLE)A whole-body autoimmune condition; vitamin D, magnesium and monitoring.

• Autoimmune and inflammatory conditions
• Coimbra Protocol

This page is for education and does not replace medical advice. Do not start, stop or change any medicine or supplement without medical guidance.

References

1. National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), US National Institutes of Health. Psoriatic arthritis. niams.nih.gov/health-topics/psoriatic-arthritis

2. Alinaghi F, et al. Prevalence of psoriatic arthritis in patients with psoriasis: A systematic review and meta-analysis of observational and clinical studies. J Am Acad Dermatol 2019;80(1):251-265.e19. doi:10.1016/j.jaad.2018.06.027

3. Radić M, et al. Vitamin D in psoriatic arthritis – A systematic review and meta-analysis. Semin Arthritis Rheum 2023;60:152200. doi:10.1016/j.semarthrit.2023.152200

4. Xie W, et al. Modifiable lifestyle and environmental factors associated with onset of psoriatic arthritis in patients with psoriasis: A systematic review and meta-analysis of observational studies. J Am Acad Dermatol 2021;84(3):701-711. doi:10.1016/j.jaad.2020.08.060

5. Nguyen Y, et al. Efficacy of Oral Vitamin Supplementation in Inflammatory Rheumatic Disorders: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Nutrients 2020;13(1). doi:10.3390/nu13010107

6. Ford AR, et al. Dietary Recommendations for Adults With Psoriasis or Psoriatic Arthritis From the Medical Board of the National Psoriasis Foundation: A Systematic Review. JAMA Dermatol 2018;154(8):934-950. doi:10.1001/jamadermatol.2018.1412

7. NHS. Psoriasis: treatment. nhs.uk/conditions/psoriasis/treatment

8. Theodoridis X, et al. Effectiveness of oral vitamin D supplementation in lessening disease severity among patients with psoriasis: A systematic review and meta-analysis of randomized controlled trials. Nutrition 2021;82:111024. doi:10.1016/j.nut.2020.111024

9. Hahn J, et al. Vitamin D and marine omega 3 fatty acid supplementation and incident autoimmune disease: VITAL randomized controlled trial. BMJ 2022;376:e066452. doi:10.1136/bmj-2021-066452

10. Finamor DC, et al. A pilot study assessing the effect of prolonged administration of high daily doses of vitamin D on the clinical course of vitiligo and psoriasis. Dermatoendocrinol 2013;5(1):222-34. doi:10.4161/derm.24808

11. Gossec L, et al. EULAR recommendations for the management of psoriatic arthritis with pharmacological therapies: 2023 update. Ann Rheum Dis 2024;83(6):706-719. doi:10.1136/ard-2024-225531

12. Office of Dietary Supplements, US National Institutes of Health. Vitamin D: Fact Sheet for Health Professionals. ods.od.nih.gov/factsheets/VitaminD-HealthProfessional

13. Klingberg E, et al. Weight loss improves disease activity in patients with psoriatic arthritis and obesity: an interventional study. Arthritis Res Ther 2019;21(1):17. doi:10.1186/s13075-019-1810-5

14. Di Minno MN, et al. Weight loss and achievement of minimal disease activity in patients with psoriatic arthritis starting treatment with tumour necrosis factor α blockers. Ann Rheum Dis 2014;73(6):1157-62. doi:10.1136/annrheumdis-2012-202812

15. Gwinnutt JM, et al. 2021 EULAR recommendations regarding lifestyle behaviours and work participation to prevent progression of rheumatic and musculoskeletal diseases. Ann Rheum Dis 2023;82(1):48-56. doi:10.1136/annrheumdis-2021-222020

16. NHS. Psoriatic arthritis. nhs.uk/conditions/psoriatic-arthritis

17. Agca R, et al. EULAR recommendations for cardiovascular disease risk management in patients with rheumatoid arthritis and other forms of inflammatory joint disorders: 2015/2016 update. Ann Rheum Dis 2017;76(1):17-28. doi:10.1136/annrheumdis-2016-209775

18. Taylor W, et al. Classification criteria for psoriatic arthritis: development of new criteria from a large international study. Arthritis Rheum 2006;54(8):2665-73. doi:10.1002/art.21972

19. Haroon M, et al. Diagnostic delay of more than 6 months contributes to poor radiographic and functional outcome in psoriatic arthritis. Ann Rheum Dis 2015;74(6):1045-50. doi:10.1136/annrheumdis-2013-204858

20. Roger-Silva D, et al. A resistance exercise program improves functional capacity of patients with psoriatic arthritis: a randomized controlled trial. Clin Rheumatol 2018;37(2):389-395. doi:10.1007/s10067-017-3917-x

21. Amon U, et al. Safety Data in Patients with Autoimmune Diseases during Treatment with High Doses of Vitamin D3 According to the “Coimbra Protocol”. Nutrients 2022;14(8). doi:10.3390/nu14081575

22. Feige J, et al. Vitamin D Supplementation in Multiple Sclerosis: A Critical Analysis of Potentials and Threats. Nutrients 2020;12(3). doi:10.3390/nu12030783

23. Uwitonze AM, Razzaque MS. Role of Magnesium in Vitamin D Activation and Function. J Am Osteopath Assoc 2018;118(3):181-189. doi:10.7556/jaoa.2018.037

24. Gwinnutt JM, et al. Effects of diet on the outcomes of rheumatic and musculoskeletal diseases (RMDs): systematic review and meta-analyses informing the 2021 EULAR recommendations for lifestyle improvements in people with RMDs. RMD Open 2022;8(2). doi:10.1136/rmdopen-2021-002167

25. Kristensen S, et al. Beneficial effect of n-3 polyunsaturated fatty acids on inflammation and analgesic use in psoriatic arthritis: a randomized, double blind, placebo-controlled trial. Scand J Rheumatol 2018;47(1):27-36. doi:10.1080/03009742.2017.1287304

26. Office of Dietary Supplements, US National Institutes of Health. Magnesium: Fact Sheet for Health Professionals. ods.od.nih.gov/factsheets/Magnesium-HealthProfessional

27. Tsai TY, et al. Serum homocysteine, folate and vitamin B(12) levels in patients with psoriasis: a systematic review and meta-analysis. Br J Dermatol 2019;180(2):382-389. doi:10.1111/bjd.17034

28. Scher JU, et al. Decreased bacterial diversity characterizes the altered gut microbiota in patients with psoriatic arthritis, resembling dysbiosis in inflammatory bowel disease. Arthritis Rheumatol 2015;67(1):128-39. doi:10.1002/art.38892

29. Rizzo A, et al. Gut inflammation in spondyloarthritis. Best Pract Res Clin Rheumatol 2017;31(6):863-876. doi:10.1016/j.berh.2018.08.012

30. Antonelli A, et al. High prevalence of thyroid autoimmunity and hypothyroidism in patients with psoriatic arthritis. J Rheumatol 2006;33(10):2026-8. pubmed.ncbi.nlm.nih.gov/17014017

31. Fallahi P, et al. Increased incidence of autoimmune thyroid disorders in patients with psoriatic arthritis: a longitudinal follow-up study. Immunol Res 2017;65(3):681-686. doi:10.1007/s12026-017-8900-8

32. Thrastardottir T, Love TJ. Infections and the risk of psoriatic arthritis among psoriasis patients: a systematic review. Rheumatol Int 2018;38(8):1385-1397. doi:10.1007/s00296-017-3873-4

33. Dalmády S, et al. Periodontitis: a newly identified comorbidity in psoriasis and psoriatic arthritis. Expert Rev Clin Immunol 2020;16(1):101-108. doi:10.1080/1744666X.2019.1700113

34. Bjornevik K, et al. Longitudinal analysis reveals high prevalence of Epstein-Barr virus associated with multiple sclerosis. Science 2022;375(6578):296-301. doi:10.1126/science.abj8222

35. Silva DR, et al. Effectiveness of functional training versus resistance exercise in patients with psoriatic arthritis: randomized controlled trial. Adv Rheumatol 2023;63(1):58. doi:10.1186/s42358-023-00342-y

36. Liang Z, et al. Effects of water therapy on disease activity, functional capacity, spinal mobility and severity of pain in patients with ankylosing spondylitis: a systematic review and meta-analysis. Disabil Rehabil 2021;43(7):895-902. doi:10.1080/09638288.2019.1645218

37. Rausch Osthoff AK, et al. EULAR recommendations for physical activity in people with inflammatory arthritis and osteoarthritis: 2025 update. Ann Rheum Dis 2026;85(6):1026-1038. doi:10.1016/j.ard.2026.03.006

38. Hailey LH, et al. Lifestyle Modifications and Nonpharmacologic Interventions to Improve Outcomes in Psoriatic Arthritis: A Systematic Review. Clin Ther 2023;45(9):841-851. doi:10.1016/j.clinthera.2023.05.009

39. Zhang X, et al. Characteristics and pathogenesis of Koebner phenomenon. Exp Dermatol 2023;32(4):310-323. doi:10.1111/exd.14709

40. Wu JJ, Caperton C. Images in clinical medicine. Psoriasis flare from Koebner’s phenomenon after acupuncture. N Engl J Med 2013;368(17):1635. doi:10.1056/NEJMicm1205716

41. NHS. Septic arthritis. nhs.uk/conditions/septic-arthritis

42. Coates LC, et al. Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA): updated treatment recommendations for psoriatic arthritis 2021. Nat Rev Rheumatol 2022;18(8):465-479. doi:10.1038/s41584-022-00798-0

43. Leung YY, et al. The APLAR Recommendations for the Management of Psoriatic Arthritis. Int J Rheum Dis 2025;28(8):e70372. doi:10.1111/1756-185x.70372