Background and Rationale:

Vitamin D deficiency is a major public health concern. While clinical guidelines provide treatment protocols, medication adherence remains a significant barrier to achieving target serum levels. This study aims to evaluate whether a structured patient education program can improve health beliefs and adherence, ultimately leading to better clinical outcomes.

Study Procedures:

Participants identified with Vitamin D levels <30 ng/mL will be randomized into two groups.

Intervention Group:

Patients will receive a face-to-face education session covering the importance of Vitamin D, correct usage, and potential side effects. They will also receive informative brochures and monthly follow-up phone calls to support adherence.

Control Group:

Patients will receive standard clinical care without additional structured education.Evaluation:Adherence will be monitored using the Medication Possession Ratio (MPR). Serum 25(OH)D levels and Vitamin D Health Belief Scale scores will be reassessed at the 6-month mark to compare the effectiveness of the intervention against the control group.

Inclusion Criteria:

• Female,
• Aged 18 years and older,
• Hypothyroid disease,
• Serum vitamin D level < 30 ng/mL,
• Providing written informed consent to participate in the study.

Exclusion Criteria:

• Male ,
• Under the age of 18,
• Patients who do not provide written informed consent,
• Serum vitamin D levels > 30 ng/mL

Individual participant data (IPD) will not be shared to ensure the confidentiality and privacy of the participants, in accordance with the institutional ethics committee's guidelines and local data protection regulations. The data collected during this study contains sensitive clinical information belonging to a specific patient population, and the informed consent obtained from the participants did not include permission for the public sharing or secondary use of their individual raw data by third parties