 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. 