What daily supplements do you use to support healthy development?

My 5yr is starting the process of Diagnosis, when he was 1-2 yrs old he would flap his baby hands and couldn’t keep still, that’s about it, after that the signs of autism disappeared, about 6 months ago they returned. He started PreK this year and it seems like this brought out a lot a lot! Of stimming. He’s also not following instructions in class, difficulty sitting still, teacher finds him very challenging. He’s not aggressive.

I suspect he’s lvl 1 Autism, he can read very well, can have conversations, responds to his name unless he’s hyperfixated, he plays with me and has great eye contact with me and dad, but his teacher says that not with her.

Anyways, I’ve notice a lot of stimming, I’m sure school is stressing him out. It almost seems like he’s regressing, stimming is almost out of control and it makes me sad that he’s possibly anxious. What vitamins or any other medication do you use to help your child regulate and also develop? I’m not looking to cure the autism I just want to make sure he has mental clarity and ability to regulate