Yes, once a women completes her first trimester , is put on Iron &
Calcium supplement . This is because baby needs oxygen which haemoglobin contain iron carries compensated by the mother through placenta . . When she enters 2 Nd trimester the iron starts decreasing in maternal blood as iron is transferred to foetus . So if iron supplement is not given mother will develop anaemia . So along with healthy food , iron and calcium supplements are given .