The goal of this clinical trial is to compare in the effectiveness of combining ursodeoxycholic acid and vitamin D in treating patients with primary biliary cholangitis.

A prospective analysis will be conducted on 60 patients with primary PBC who were admitted to our Infectious Diseases Department and outpatient clinic. All patients will take UDCA capsules orally and divide into two groups: the experimental group, which received UDCA combined with Vitamin D(1200 IU per day) treatment, and the control group. The control group will receive UDCA treatment alone for one year, selected through a random number table method. After one year, the control group will be further divided into two groups using the same method. One group will continue to receive UDCA alone, while the other will receive a combination of UDCA and vitamin D for an additional year. Clinical data, clinical manifestations, blood tests, and imaging tests will be collected during the initial and subsequent treatments. The efficacy will be evaluated using the Paris I and Barcelona standards.

Inclusion Criteria:

1. The patient must meet the diagnostic criteria for PBC ;
2. The patient must have been diagnosed at the age of 18 or older;
3. The patient must have completed at least 2 years of treatment and have complete and accessible clinical data;
4. The patient must have strictly followed the doctor's prescription during the treatment period and not have interrupted the treatment arbitrarily.

Exclusion Criteria:

1. The study excluded patients with autoimmune hepatitis or primary sclerosing cholangitis.
2. Patients with other acute and chronic liver diseases were also excluded.
3. Patients with serious cardiopulmonary diseases were excluded as well.
4. Pregnant or lactating women were not included in the study.
5. Patients who randomly interrupted or adjusted their medication during the treatment period were excluded.
6. Patients who lacked follow-up were also excluded.