10.22376/ijpbs.2019.10.1.p1-12 Volume 6 Issue 4 2015 (October - December) Vitamin D deficiency is known to cause complications in pregnancy. There is sparse data on the prevalence of hypovitaminosis D in pregnancy, in India. Our study was undertaken to fill this lacuna. 148 pregnant women were enrolled from SRM Medical College and Research Centre, Kattankulathur, India. Serum concentrations of 25-hydroxyvitamin D [25(OH)D lessThan sub greaterThan 3 lessThan /sub greaterThan ] and related laboratory parameters were measured. The mean 25(OH)D lessThan sub greaterThan 3 lessThan /sub greaterThan level in pregnant women was 19.05 ng/mL. Only 8 subjects (5.4%) had greaterThan 30 ng/mL (sufficient). 47 (33.7%) had 20-30ng/mL (insufficiency), 79 (53.4%) had lessThan 20ng/mL (deficiency) and, 14 (9.4%) had lessThan 10ng/mL (severe deficiency). We also found that maternal 25OH-D was associated positively to calcium (r= 0.6951, lessThan i greaterThan p lessThan /i greaterThan lessThan 0.001) and phosphorus (r= 0.6211, lessThan i greaterThan p lessThan /i greaterThan lessThan 0.001) and negatively to alkaline phosphatase (r= –0.4086, p lessThan 0.001) and parathyroid hormone (r=0.7856, lessThan i greaterThan p lessThan /i greaterThan lessThan 0.001) by Pearson's correlation coefficient method. Thus, in our study, we found an alarming total prevalence of 94.6% of vitamin D deficiency and insufficiency, among pregnant women. There is a definite need for vitamin D supplementation, in pregnant women. PAULRAJ SATHISH, RAMASAMY PADMA AND DORAISAMI BALAKRISHNAN Hypovitaminosis D, Calcium, Parathyroid hormone, pregnancy complications. 583-589