DS is now doing well with BF, gaining weight and putting on chub!

great stuff, good for you!

At his 2-week check up, the ped mentioned that if he was still
exclusively breasfed at his two month check up then they would want to
put him on a multi-vitamin because "breastmilk doesn't have vitamin D."
I've never heard of babies going on a multi-vitamin at 2 months old...is
this new? If my baby needs vitamin D, why doesn't my breastmilk have
it? The only thing I can think of is that I live in the Pacific
Northwest (US), and we don't get a lot of sun this time of year, so less
vitamin D that way?

we get vitamin D from sunlight, so amount of sun exposure is a factor,
however, although vit D supplements are recommended from 6 months in the
UK even the sun that far north is enough in winter for white skinned
babies to get the vit D they need, but it is an issue for other
ethnicities, but even then, I don't think I've heard it as early as 2
months. If you have dark skin (including hispanic colouring), it may be
something you need to consider, but you still need to get specific data
for your location, I'm not sure cloud cover makes much difference, just
the hours of sunlight. These days we also live in the PNW, our
paediatrician doesn't recommend multi vitamins, she says they are a
waste of money!

Cheers
Anne