The reason that breastmilk nourishes human babies perfectly with what
would seem sub-optimal levels of nutrients is in the presentation- many
nutrients come with carrier proteins to maximize their absorbtion, and
the balance of all the nutrients together serves to maximize the
absorbtion of each particular nutrient.  This is not the case with abm or
solid foods, so much higher levels of nutrients are neccessary for the
baby to actually use the needed amount.
--
Catherine Watson Genna, IBCLC  NYC  [log in to unmask]