(1) The use of the thiochrome method for the estimation of thiamine in human milk is discussed, with special reference to the possible production of an artefact, following the incubation of the milk with pepsin, in addition to the use of takadiastase (clarase). No evidence could be found to suggest that an artefact resembling thiamine was produced by the method of analysis described.
(2) The thiamine content of 91 samples of full lactation human milk from apparently "normal" Malay, Chinese and Indian women in Malaya is recorded. The mean milk thiamine level of 11.3 ug/100 ml. found is considerably lower than the levels recorded for milk samples from apparently "normal " women in the United Kingdom and the U.S.A.; and slightly lower than that recorded in Australia. The results suggest that the dietary
intake of thiamine in Malaya is inadequate to maintain optimum thiamine levels in the milk of lactating women.
(3) No significant difference was found in the mean thiamine content of milk from women of the three principal racial groups in Malaya ; nor was any significant difference found to be associated with the parity or age of the women or, in the case of full lactation milks, with the time after parturition at which the sample was collected. No significant difference was found in samples collected from the same woman at different times of the day or before and after a main meal.
(4) Marked differences were found in the thiamine content of samples of milk from individual women, and the possible reasons for this are discussed.
(5) The examfnation of 48 samples of milk collected during the first month after parturition confirmed previous recorded observations that the thiamine content of such milks, initially low, gradually increases to reach "normal" levels towards the end of the first month of lactation.
(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.