Are teenagers growing more rapidly in the summer and spring than during the winter? or in other words... are teenagers growing more rapidly in the summer vacation than school year?(because of getting more vitamin d from the sun, sleeping more etc?

interesting question. I know of no data on this but you can track this yourself. Measure weight in the nude every day to nearest gm you can. And measure height every day to nearest mm without shoes. Plot daily and see on yourself. Go to pubmed.gov and search the world lit. Enter growth rate AND season to see if anyone one studied this well.