Поскольку иглы относятся к предмета

Поскольку иглы относятся к предметам, которые нельзя брать с собой на борт, тебе нужно будет показать справку о диабете на пограничном контроле и, возможно, экипажу самолета.

Результаты (английский) 1:

Because the needles are among the subjects that you cannot take with you on board, you will need to show help about diabetes on border control and, perhaps, to the aircrew.

Результаты (английский) 2:

Since needles are subjects that can not take on board, you will need to show a certificate of diabetes at the border control and, possibly, to the crew.

Результаты (английский) 3:

Since needles are to the subjects, which is not to take on board, you will need to show help about diabetes at the border control and, possibly, the aircraft crew.