(1) The effect has been studied of the oral administration of supplementary thiamine on the thiamine content of milk from sixteen women, whose initial thiamine content was low ; and of the parenteral administration of thiamine to ten women, some of whom initially showed mild, clinical symptoms of beriberi.
(2) The response in the milk content of thiamine to supplementary thiamine, administered either orally or by injection, showed marked variation in different women. While comparatively small doses taken by mouth evoked a marked response in some women, fairly large doses administered by injection failed to produce much response in others.
(3) In some women, a marked increase in the thiamine content of their milk occurred soon after the administration of thiamine, either orally or parenterally. In others, the response was slow and meagre.
(4) The highest thiamine level obtained in a sample of milk was 38.9 ug./100 ml., after the injection, twice daily, of 20 mg. thiamine for six days — a total intake of 240 mg. of thiamine parenterally. The initial milk thiamine level in this case was 2.3 ug./100 ml., but had increased to 16.2ug./100 ml., by the supply of a good diet alone, before the course of injections was commenced.
(5) It would appear, that, in cases where the thiamine content of the milk is low, initial parenteral administration of thiamine must be supplemented by a continued intake of additional thiamine, if a satisfactory level of thiamine in the milk is to be maintained.