AbstractIntroduction: Vitamin D deficiency is being suggested as a cardiovascular risk-factor. The present study was conducted to assess the association of vitamin D deficiency with the severity of coronary artery disease (CAD). Methodology: Vitamin D level was measured in patients who underwent coronary angiography in our department. CAD was defined as patients with angiography proven stenosis of ≥ 50% in at least one major coronary arteries. Results: Of 86 patients, 66% were diagnosed with CAD. The vitamin D level in these patients was significantly lower as compared to those with normal coronary. Vitamin D level was also found to be significantly associated with the severity of CAD in terms of the number of vessels involved. Among all patients with single vessel disease (n = 17), two patients had vitamin D level less than 20 ng/ml, 10 had vitamin D level 21 to 30 ng/ml and rest had vitamin D higher than 30 ng/ml. Among the 20 patients with double vessel disease, 9 had vitamin D level between 21 to 30 ng/ml and lower than 20 ng/ml each. Among the 20 patients with triple vessel disease, 11 patients had vitamin D levels below 20 ng/ml. This association was found to be statistically highly significant. Conclusion: Vitamin D deficiency was associated with angiographic severity of CAD. Low vitamin D level may be an emerging, independent and reversible cardiovascular risk-factor.