Aim: The aim of the present study was to determine the vitamin D status of pregnant mothers and its effect on anthropometric measures in the offspring. Methods: A prospective observational study was conducted in the Department of Obstetrics & Gynaecology and Department of Pediatrics, Narayan Medical College and Hospital, Sasaram, Rohtas, Bihar, India, between February 2019 to January 2020. Convenient sampling technique was employed and all mothers attending the antenatal clinic in their 3rd trimester, after taking the proper informed consent were enrolled in this study. Gestational age was calculated using mother’s 1st day of last menstrual period and/or 1 st trimester ultrasonography. Fetal growth restriction of the baby was defined as birth weight below the 10th percentile for the gestational age. Venous blood samples were taken and transported to the biochemistry laboratory. Serum separation was done without delay and stored at appropriate temperature. Length of Infant was measured with an Infantometer. Nonstretchable plastic tape was used to measure head circumference of Infants. Results: Total 102 pregnant mothers in their third trimester were enrolled in this study for final analysis. Maternal serum 25(OH) D<12 ng/ml was found in 19% of the mothers and 46% mothers had values 12-20 ng/ml. This means 65% of women in their 3rd trimester were not having sufficient Vitamin D3 in their body. Maternal Mean serum PTH was 27.1 (SD: 21.23). However, maternal serum PTH showed a significant negative correlation with maternal 25(OH) D (r= -0.317, p= 0.0007). Further, median level of PTH was significantly higher (p=0.001) in 25 (OH) D deficient group (21.9 pg/ml) when compared to nondeficient group (11.17pg/ml) according to Mann-Whitney test. PTH showed a significant correlation to calcium, alkaline phosphatase and inorganic phosphorus according to Spearman’s correlation coefficient test. Anthropometry of the infants at birth and at one month of age was taken. Correlation between biochemical parameters (vitamin D, PTH) and growth (weight, length, OFC) was not significant. Conclusion: A significant rate of vitamin D deficiency was observed in pregnant mothers. There was no correlation between maternal vitamin-D3 levels in 3rd trimester of pregnancy and neonatal anthropometry in this study.