Sir.-I have two questions concerning the letter by Bhowmick et al1 that appeared in the February 1991 issue of AJDC. First, in the last paragraph of the letter, the authors stated, "Although it may be true that some breast-fed infants do not routinely need vitamin D supplements, we do recommend 400 IU of supplementary vitamin D per day in all breast-fed black infants regardless of geographic location." I want to know what the authors meant by "some."
The second issue pertains to the quality of evidence that "proves" that this regimen adequately prevents rickets. No reference was given for that claim, and I am eager to know the source