The midwives and HVs you work with are wrong, nurseryjo.
And Louise, the comment you heard on the Vanessa show is also wrong.
This is milk we are talking about, made by human mothers for human babies.
At 11 months 29 days, it is of nutritional benefit, healthy, protective, good all round. And then as soon as the child is one, somehow or other it ceases to be of any value. How does that work, then? Turns to water overnight? Huh?
What about cows at some distance from having calved? Better tell the farmers to cease milking them, because at a certain point, their milk is of no nutritional value.
When babies are of an age and stage to take a variety of solid foods, then breastmilk becomes less essential nutritionally - naturally enough. When the baby is taking nothing but breastmilk, then of course it is of vital importance in keeping him well fed. But solids do not mean the milk is of 'little nutritional benefit' or in the words of the Vanessa show (that well known source of excellent info), 'definitely of no nutritional benefit'.
It's still milk, full of antibodies, full of good stuff, keeping babies healthy and growing.
I despair, really, sometimes. I enjoy Mumsnet being a forum for opinion, but posters really ought to take a second or two to think logically, before presenting something daft they have heard as if it was fact, from unreliable sources (yes, I include midwives and health visitors in that, sadly).