Poor vitamin D status is very common in African Americans. Periodontitis (gum disease) are shown to be related to theincreased risk of cardiometabolic diseases. Vitamin D is freely available and cheap supplement that has shown beneficialeffect in the immune system regulation and maintenance of the cardiovascular health. In this study The investigators hypothesize thatvitamin D supplementation for 16 weeks in African Americans with periodontitis will result in clinical improvement in theirgum health as well as their cardiometabolic risk profile

This is a double-blind placebo-controlled randomized clinical trial of vitamin D supplementation.

The eligible subjects will be assigned to a specific group by random assignment in one of the following two groups:

1. Group 1 who will receive placebo.
2. Group 2 who will receive 4,000 IU vitamin D.

Both groups will receive either the placebo pills or vitamin D supplementation everyday for 16 weeks. At visit 1: a fasting morning urine sample will be collected. Height, weight, hip and waist circumferences will be measured. Automatic and manual blood pressures will be measured in sitting position. Approximately 80 ml of venous blood will be collected. Arterial stiffness will be assessed non-invasively by the SphygmoCor device. This device also measures the central (aortic) BP and simultaneously measures pulse wave velocity (PWV). A bottle of 30 capsules containing either vitamin D or placebo will be given to the subjects and will be asked to take one capsule every day for next month till the second visit. A questionnaire to assess the dietary habits, tobacco use, sun exposure, physical activity, socio-economic status and family health history will be given to the subject. At the dental clinic, full mouth clinical measurements (periodontal probing) will be performed. A plaque sample will be taken and a gum biopsy will be taken to examine the dendritic cells. Also, a saliva sample will be collected.

At visit 2: one month later, the supplements will be replenished, compliance will be assessed, and subjects will be examined for any potential side effects.

At visit 3: at 8-week follow up, anthropometric measures, blood samples as well as BP and PWV will be measured and the subject will be assessed for clinical improvement in the periodontitis. All the subjects, irrespective of their group assignment will undergo intensive scaling and root planing (S&RP). The supplements will be replenished, compliance will be assessed, and subjects will be examined for any potential side effects.

Another fasting blood draw, BP measurement and PWV will be performed approximately 24 hours after the S&RP. Also, the investigators will collect saliva sample during this visit.

At visit 4: at 12-week follow up, the procedure in this visit are similar to the visit 2.

At visit 5: at 16-week follow up, a post-test evaluation of vitamin D status, cardiovascular phenotypes and periodontitis will be done at the end of the study.

Inclusion Criteria:

1. You are African American
2. You have generalized chronic moderate to severe gum disease (periodontitis)
3. Your age is between 18-60 years.
4. You are not taking any vitamin, mineral or herbal supplements
5. If you are a female, you are not pregnant

Exclusion Criteria:

• Not meeting any of the above