IRCT20221212056786N3 IRCT 2023-11-05 Yazd University of Medical Sciences Evaluation the effect of vitamin D3 in improvement clinical parameters of patients with chronic periodontitis-clinical trial Evaluation the effect of vitamin D3 in improvement clinical parameters of patients with chronic periodontitis-clinical trial 2023-12-11 anticipated 32 Complete https://irct.ir/trial/73543 interventional Randomization: Randomized, Blinding: Double blinded, Placebo: Used, Assignment: Parallel, Purpose: Treatment, Randomization description: Eligible patients are placed in two groups using Random Allocation software version 1.0 under Windows and stratified in a simple random manner based on age so that the two groups are the same in terms of age, Blinding description: In this study, the study participants and the researcher will be unaware of the division of patients into experimental and control groups, and only a third person outside the study will be aware of the division method. (double-blinding) Vitamin 3D supplement and placebo will be provided to patients in the same containers. (so that the contents of the containers are not visible from the outside). 4 Chronic periodontitis. Intervention 1: Intervention group: The ingredient used is vitamin D3 4000 soft gel in yellow color. Two 4000 IU vitamin D3 oral supplement capsules (Dana Pharmaceutical Company product) daily, one in the morning and one at night, will be given to the patients of this group every day (seven days a week) for 12 weeks. Intervention 2: Control group: They will receive the placebo in the form of a soft gel without the active ingredient, which is similar in size and color to vitamin D3. The patient should take one pill in the morning and one pill at night, every day (seven days a week) for 12 weeks. Undecided - It is not yet known if there will be a plan to make this available Justification or reason for indecision in sharing IPD is There is no further information