The study is planned as a randomized open label interventional trial. The study will be conducted of 50 adult patients (25 interventional group, 25 control), all from the internal ward in "Meir" medical center. Patients which are admitted after an acute coronary event will be randomized to the Vitamin D supplementation group or to the control group. the vitamin D group will receive 4000IU per day of vitamin D for five days. Cytokine levels will be measured at day 1 and at day 5. follow up will be continued for 6 months