Why not just supplement the baby until mom's vitamin D status is
improved?

From Nutrition During Lactation, Institute of Medicine, 1991.  "In
summary , exclusive breastfeeding results in normal infant bone
mineral content when maternal vitamin D status is adequate and the
infant is regularly exposed to sunlight.  If the infant or mother is
not exposed regularly to sunlight, or if the mother's intake of
viatin D is low, supplements for the infant may be indicated (5 - 7.5
ug/day)."

Also from same reference:  "Breastfed infants require approximately
30 minutes of exposure to sunlight per week if wearing only a diaper,
or 2 hours per week if full clotherd without a hat to maintain normal
serum 25-hydroxycholecalciferol levels.  Darkly pigmented infants
require a greaster exposure to sunshine to initiate the sysntheseis
of vitamin D in the skin."

 See the book for  additional information.

Also note that good vitamin D status  is important for the
mother's health as well as for the infant.

Mary B Johnson
Minnesota WIC Program