The goal of this prospective, randomized, parallel-group design, double-blind, and 6-month follow-up is to evaluate the impact of 4000 IU/day vitamin D on 25-hydroxyvitamin D [25(OH)D] levels and inflammatory mediators in people with Rheumatoid Arthritis (RA).

The main questions it aims to answer are

• The level of 25(OH)D and inflammatory mediators of levels of RA differs at baseline and after 6 months of Vitamin D 4000 UI
• The disease activity of AR measured by visual analogue scale (VAS) and Disease Activity Score-28 (DAS-28 score) will change in baseline and after 6 months of Vitamin D 4000 UI Researchers will compare the group of participants with Vitamin D supplementation and group of participants without D Vitamin supplementation

Participants in active group will:

• Take Vitamin D every day for 6 months
• Visit the clinic in the first months and after 6 months for medical visits and tests.

Rheumatoid arthritis (RA) is an idiopathic autoimmune disease with a chronic course of exacerbations and remissions with more frequent incidence in females, characterized by inflammation, pain, and progressive damage to the joints. The main focus of our study is to evaluate the impact of Vitamin D besides other standard therapies in the group of people with RA, assessing the inflammatory mediators and clinical course of the disease in the baseline and after six months.

This is a prospective, randomized, controlled Trial (RCT) with a Parallel-Group Design, ensuring that changes in inflammation markers and disease activity over time will be measured simultaneously and independently.

Before enrolment, the research dossier, including the patient's informed consent, was submitted to the Medical Chamber of Kosovo Ethics Committee for approval. This professional body approved this study, and the approval letter was issued to the research team. Patients were included in the study only after signing the consent form and after being fully informed about the research.

The participants will be patients which fulfils the diagnostic criteria for Rheumatoid Arthritis (RA) of American college of Rheumatology (ACR)/European league against rheumatism (EULAR) - ACR/EULAR 2010. The cohort of participants will be elected after evaluation of inclusion and exclusion criteria of participants:

The trial participants will be enrolled from a cohort of people with RA disease treated at the University Clinical Centre of Kosovo-Rheumatology Clinic in Prishtina. The data will be collected for one year.

In both group of participants at the baseline will be measured the level of 25-hydroxyvitamin D [25(OH)D] and inflammatory mediators of RA: Interleukin 6 (IL6) , Interleukin 17 (IL17), CRP, TNF-alpha). Moreover, in both groups participants will be determined the activity of disease measuring the visual analogue scale (VAS) and Disease Activity Score-28 (DAS-28 score). The intervention group of participants will receive the Vitamin D supplementation for 6 months while other group of participants will not receive the Vitamin D and after 6 months will be evaluated level of [25(OH)D] and inflammatory mediators of RA: Interleukin 6 (IL6) , Interleukin 17 (IL17), CRP, TNF-alpha) and VAS and Das28 and compare with baseline data.

Inclusion criteria

• Rheumatoid Arthritis Caucasian patients,
• Kosovar ethnicity,
• Both genders,

Inclusion criteria:

• Patients with proven rheumatoid arthritis diagnosis ACR/EULAR 2010 grouped into four classifications with point scores for each:

  • joint symptoms;
  • serology (including RF and/or ACPA);
  • symptom duration, whether <6 weeks or >6 weeks; and
  • acute-phase reactants (CRP and/or ESR). Point scores ≥6/10 was criteria for AR diagnosis;

• RA disease duration 1-14 years

Exclusion criteria:

• Other inflammatory diseases;
• Thyroid and parathyroid diseases;
• Liver and kidney disease;
• Last 3 months treatment with Ca > 1g/per day;
• Last 3 months treatment with vitamin D supplements