lots of babies who are weaned at 12 months(ff or bf) are ok to not have milk or dairy. calcium can be sourced from LOTS of other foods and is infact better absorbed then dairy products.

the WHO rec are that for optimum health babies should be breastfed for 2 years when not bf they are ff because this is for nutrition not for (optimum) health it can be stopped at 12 months or continued for as long as parents want(like BFing)

Full cream is a must it is CRUCIAL for the brain do not skimp on this.

a tip for yoghurt is serve him yoghurt that is very close to the useby date as the enzymes in it 'eat' the lactose in it so the older it is the less lactose it has.

also maybe try a baby probiotic for a little while to improve his gut health.

when he first had cheese and yoghurt was there lots of dairy in his diet? as dairy overload in babies is often the same as dairy intolerance