Is 21.56lbs weight normal for a 1 year and 6 months old baby? because he is picky eaters what vitamins can i give to him?

Family practice : An 18 mo ave wt is 24 lbs. Your child may be a little low on the wt scale. But several things may affect where your child places on the growth chart. Ht. Sex. Has there been a steady increase in wt or has it plateaued a baby's wt also may be affected with breast feeding. As they become more active they lose some baby fat. So watch the curve.