Low vitamin B12 and folate levels in expectant mothers may lead to low stores in babies. The aim of this study was to determine the frequencies of vitamin B12 and folate deficiencies in pregnant women and neonates, and to assess the effect of maternal vitamin status on babies' vitamin levels in the Aegean region of Turkey, where the Mediterranean diet (mainly fresh fruits and vegetables) is adopted. We studied 72 pregnant women and their singleton-term babies. Venous blood samples of expectant mothers were collected 1 h before delivery and cord blood of babies were obtained at birth. The mean vitamin B12 in maternal and cord blood serum was 163.1 ± 72.0 pg/mL and 146.2 ± 102.5 pg/mL, and the mean folate, 9.8 ± 4.8 ng/mL and 15.8 ± 3.8 ng/mL, respectively. There were statistically significant correlation between maternal and cord blood serum vitamin B12 (r = 0.61, P = .04) and folate levels (r = 0.65, P < .001). 70.8% of the mothers and 83.9% of the babies were vitamin B12 deficient (<200 pg/mL). Neither group showed folate deficiency. The mean level of vitamin B12 in mothers significantly varied by the type of diet (241.6 (72.1) pg/mL versus 155.9 (68.2) pg/mL; P = .012). Vitamin B12 deficiency in pregnant women and neonates may be a public health problem in our community. The Mediterranean diet in these vulnerable groups may be an aggravating factor for vitamin B12 deficiency. Prenatal screening of all expectant mothers, prenatal supplementation of vitamin B12, and an increase in animal-source food intake may improve expectant mother's vitamin B12 level.