> About measuring bilirubin in breastmilk-the usual lab methods used for > bilirubin would not be able to do it Although it is interesting to know what levels of anything are present in the mom's milk, I thought the clinical importance was what amount actually gets absorbed by the baby. So what (as in mag sulfate) if it is in the milk but can't cross the gut? Measuring the baby's levels are far easier, standard, accessible, cost-effective and is actually where the clinical significance lies. It *does* require a specialty lab if one is interested in BM levels of anything. When I worked peds-GI at Childrens Hospital Los Angeles and we saw a 2 yo with a diagnosis of kwashiorkor (BFer and true vegan baby of a true vegan mom - ie, non-lacto-ovo vegans), the question came up about measuring B12 levels and some other things in mom's milk. We tracked down an industrial specialty lab that could do it, but for exhorbitant 3-digit prices.