underweight baby

7.1 kgs si baby noong 11 months old. 7 kgs naman sya ngayong 12 months old. Pure breastfed sya at kakaubos lang ng vitamins nyang pedcee. Now thinking to switch to other vitamins na makakapagpagana kay baby kumain. Mahina sya kumain, kaunting portion pa lang nasusubo, aayaw na. Iluluwa yung food or ilalayo yung spoon. Sina-suggest ng parents ko na imix feed ko na daw ng formula siince 1 yr old naman na daw. Pahingi naman po advice/tips. Vitamins, food, or anything na makakapagpataba kay baby.. as much as possible po ayoko iformula milk si baby.