Maternal plasma vitamin D levels across pregnancy are not associated with neonatal birthweight: findings from an Australian cohort study of low-risk pregnant women

Table 2 Mean maternal vitamin D levels across pregnancy and use of vitamin D supplements

Vitamin D measure	mean ± SD or n (%)
Serum 25(OH) D (nmol/L)
Early pregnancy (n = 185)	83.8 ± 22.6
Mid pregnancy (n = 208)	96.5 ± 28.9*
Late pregnancy (n = 162)	100.8 ± 30.8**
Vitamin D deficiencyª
Early pregnancy (n = 185)	12 (6.5%)
Mid pregnancy (n = 208)	13 (6.3%)
Late pregnancy (n = 162)	11 (6.8%)
Taking pregnancy vitamin D supplement (n = 219)	214 (97.7%)
vitamin D supplement only (n = 214)	14 (6.5%)
Pregnancy multivitamin only (n = 214)	80 (37.4%)
vitamin D supplement plus pregnancy multivitamin (n = 214)	120 (56.1%)
Vitamin D supplement use by region of birth (n = 219)	mean ± SD or n (%)
High risk for vitamin D deficiency^b	78 (35.3%)
vitamin D supplement only	5 (6.4%)
Pregnancy multivitamin only	17 (21.8%)
vitamin D supplement plus pregnancy multivitamin	55 (70.5%)
Not taking any form of VD supplement	1 (1.3%)
Not high risk for vitamin D deficiency^c	145 (64.7%)
vitamin D supplement	9 (6.3%)
Pregnancy multivitamin only	63 (44%)
vitamin D supplement plus pregnancy multivitamin	65 (45.5%)
Not taking any form of VD supplement	4 (2.6%)

*Paired-samples t-test result p < 0.05 comparing mean (SD) of early pregnancy vitamin D and mid pregnancy vitamin D **Paired-samples t-test result p < 0.05 comparing mean (SD) of early pregnancy vitamin D and late pregnancy vitamin D
ªVitamin D deficiency defined as serum 25(OH)D < 50 nmol/L
^bRegion of birth considered high risk for vitamin D deficiency (includes Asia/ South Asia/ Middle East/ Africa/ South America);
^cRegion of birth considered not high risk for vitamin D deficiency (includes Australia/New Zealand/ Europe/ UK/ Canada)

ISSN: 1471-2393