A door for selectively opening and closing at least a portion of an opening in a vehicle includes an outer door panel and an inner door panel. The inner panel is attached to the outer panel thus defining a space between the inner and outer panels. The door also includes a tubular reinforcement beam disposed in the space between the inner and outer door panels. The tubular reinforcement beam is attached to the door and has varying material thicknesses. A vehicle having a vehicle body that defines an opening and a subject door configured to selectively open and close at least a portion of the opening is also disclosed.