your welcome. i had a same problem on my baby's weight and i really it can help you and your bb. but please reminded that i used almost a year to improve my bb's weight and it's unable to upgrade your bb's weight immediately cos it's not a仙丹and the result depends on how long you give your bb to eat.
vitamin drops:有分大細b, but i don't know how old of your bb, so i gave the info to you after you select by yourself. 細b嗰隻---from newborn to 4 months=='tri.vi.sol.' around $35-$45, 大b嗰隻---from 4 months==='poly.vi.sol.' around $45-$55. as per my doctor said, 細b嗰隻can eat until 1 year old, so i changed大b嗰隻for my bb start from 13 months. you can buy from藥房/屈x氏/萬x, but藥房會平d.
vitamins candy: only 1 type==='jungamals', but i buy from my doctor here, the price is $270/90 tabs (1 tab for 1 day). in the market, vitamins candy are many kinds of brands, you can also choose another similar one from outside too. if you really to try this one, i can help to buy if necessary.
Try to buy some Vitmins drops with Lysine which is for the fussy-eater. But I cannot see the improvement now because my mother-in-law refuse to give it to my BB