For me Iron! so red meat and leafy green casue i get pretty anemic when pg, but il start a suppliment soon. i recon aslong as your eating a ballanced diet your right. i dont think i could live without milk when pg, but thats just my body making me get up at 2am and skull milk from the carton!!
maybe there is a recomened cal intake for when you are pg which is different to non-pg but i dont know