need some advice on my sick 2 month chick

[chickadea]

I have a small flock of chicks which just got smaller by one. I recently lost my sweet lil silkie to what I researched thought it was vitamin deficiency. She was fine then I went to feed them,and she was on her side couldn't stand up was flapping her wings and moving her feet while on her side. I brought her into the house to monitor her. She was very sleepy I gave her some fruit she ate then some vitamin water. I keep her wrapped so she wouldn't flap her wings. After 2 days she passed away. Now today I go into the coop and I have a sleepy chick. Which is out of character for my polish gal. I'm not sure what to do. Is it something more then vitamin deficiency? They recently started playing in the run. The chicks are almost 2 months some younger a few days some a few days older. They have treats as of now just fresh fruit and veggies. I'm not sure what more info I could give? pls if anyone have some advice it would be apriciated thanks so much

 

[chickadea]

Something's I forgot to add.... I recently started them on growers feed, also check the poop no blood fairly normal looking, and after my silkie died I added vitimen water to the flicks water as a preventive. Thanks again