A vapor deposition device includes a reactor including a reaction chamber and an injector for injecting vapor into the reaction chamber. The device also includes a manifold for delivering vapor to the injector. The manifold includes a manifold body having an internal bore, a first distribution channel disposed within the body in a plane intersecting the longitudinal axis of the bore, and a plurality of supply channels disposed within the body and in flow communication with the first distribution channel and with the bore. Each of the first supply channels is disposed at an acute angle with respect to the longitudinal axis of the bore, and each of the supply channels connects with the bore at a different angular position about the longitudinal axis. The distribution channel (and thus, the supply channels) can be connected with a common reactant source. Related deposition methods are also described.