An oral spray solves a specific problem: B12 absorption depends on intrinsic factor in the stomach, and that becomes less reliable with age and with some medications. Spraying into the mouth sidesteps the question of whether a tablet will be broken down properly.

The B12 here is methylcobalamin, the form already active in the body, rather than cyanocobalamin which has to be converted first.

A dose is four sprays, delivering 100 micrograms. Sweetened with xylitol, preserved with potassium sorbate at 0.15 percent, and that is the whole formulation.

Suitable from one year old, which makes it one of the few B12 options that works for a young child and an adult out of the same bottle.

Twenty millilitres. Can be taken with or without food.