Peer-reviewed studies going back over half a century indicate that inhalation is an extremely effective way of absorbing vitamin B12. After only one dose they indicate immediate absorption.
Vitamin B12 is an extremely important part of your dietary intake.
According to the National Institute of Health: "Vitamin B12 is a nutrient that helps keep the body's nerve and blood cells healthy and helps make DNA, the genetic material in all cells.
Vitamin B12 also helps prevent a type of anemia called megaloblastic anemia that makes people tired and weak."