Vitamin D status in mothers with pre-eclampsia and their infants: a case-control study from Serbia, a country without a vitamin D fortification policy

Objective: The objective of the present study was to determine if vitamin D intake and status are associated with pre-eclampsia in a country without a vitamin D fortification policy. Design: A case-control study of pregnancies with (case) and without (control) pre-eclampsia was conducted from January to April when UVB is minimal. Maternal and cord blood obtained at delivery were measured for plasma 25-hydroxycholecalciferol (25-OH-D-3), 3-epimer of 25-OH-D-3 (3-epi-25-OH-D-3) and 24,25-dihydroxycholecalciferol (24,25-(OH)(2)D-3) by LC-MS/MS and maternal 1,25-dihydroxyvitamin D (1,25-(OH) 2D). Differences between groups were tested with ANOVA and Bonferroni post hoc tests (P < 0.05). Setting: Clinical Center of Serbia. Subjects: Pregnant women with and without pre-eclampsia (n 60) and their infants. Results: Exogenous vitamin D intake (0.95-16.25 mu g/d (38-650 IU/d)) was not significantly different between groups. Women with pre-eclampsia delivered infants at an earlier gestational age and had significantly lower mean total plasma 25-hydroxyvitamin D (25-OH-D; case: 11.2 (SD 5.1); control: 16.1 (SD 5.7) ng/ml; P=0.0006), 25-OH-D-3 (case: 10.0 (SD 4.9); control: 14.2 (SD 5.8) ng/ml; P=0.002), 3-epi-25-OH-D-3 (case: 0.5 (SD 0.2); control: 0.7 (SD 0.2) ng/ml; P=0.0007) and 1,25-(OH)(2)D (case: 56.5 (SD 26.6); control: 81.0 (SD 25.7) pg/ml; P=0.018), while 24,25-(OH)(2)D-3 was not different between groups. Infants did not differ in total plasma 25-OH-D, 25-OH-D-3, 3-epi-25-OH-D-3 and 24,25-(OH)(2)D-3, but the mean proportion of 3-epi-25-OH-D-3 was higher in the infant case group (case: 7.9 (SD 1.1); control: 7.0 (SD 1.4) % of total 25-OH-D-3; P=0.005). Conclusions: A high prevalence of vitamin D deficiency, as defined by plasma 25-OH-D<12 ng/ml, was observed in 47 % of all mothers and 77 % of all infants. These data underscore the need for prenatal vitamin D supplementation and a food fortification policy in Serbia.