Hello, greetings! Thanks for the query. I would like to tell you that a person's height depends on his heredity status and very little on external environmental factors. Usually by the age of 21 most of the bones are fused and thus, after 21 years of age height growth is minimal. Please advise your brother to maintain a healthy diet rich in vitamins, dairy products such as milk, cheese. Including greens and sprouts is equally important. No medicines may help in this situation but he can concentrate rather, on building a lean and athletic body to make him look taller.