VDR and vitamin D deficiency: Our results showed that: (1) maternal vitamin D deficiency (25OHD < 30 nmol/L) was inversely associated with birth weight, head circumference and crown–heel length; (2) neonatal SNPs, VDR rs2228570 and GC rs4588, were significantly associated with birth weight and head circumference, respectively; and (3) a potential interaction was observed between maternal VDR rs2228570 with maternal vitamin D deficiency on head circumference.