10 year old son’s height

Hello, Is there anything that can be done to improve height in a 10 year old boy with high autoantibodies but normal TSH/T4? My 10 year old was diagnosed with celiac and Hashimotos at age 6. He is slightly below average in height, but every time he’s measured, his percentile is a little lower. His free t4 and TSH are still normal, but he has very high TPO antibodies (2500). I dont think they’ll give him synthroid yet, but is there anything else? thanks so much