Further observations on the significance of the blood pyruvic acid level in infancy.

In a previous paper it was shown (Allibone and Fich, 1946) that toxic and infective states raised the blood pyruvic acid level in spite ofwhat normally would have been an adequate thiamine intake. Ihis phenomenon was particularly noticeable in infancy. Two factors had now to be considered The first was whether the vitamin was being absorbed. Diarrhoea, which obviously would interfere with absorption, is particularly common in toxic states in infancy. In the group of infants observed above, diarrhoea, though frequent, was not an invariable manifestation -and in these particular cases had not been severe. Nevertheless such a possibility needed to be excluded. The second problem was whether, under such crcumstances, an increased intake might be necessary to achieve the greatest metabolic efficency. Abbasy et al. (1937) had shown that in infective states there was an increased utilization of vitamin C as determined by blood levels and urinary excretion. Further support for the latter possibility was to be found in the observations that the blood pyruvic acid became elevated in association with an increase in the environmental temperature (Mills, 1943) and in thyrotoxicosis (Davis and Bauer, 1944), when a raised basal metabolic rate was probably the cause. To investigate these possibilities it was decided to follow up infants who appeared likely to have a persistently high blood pyruvic acid, that is cases of marasmus, to give such infants a trial period on a physiological dose of thiamine and then, if the blood levels remained high, to give the vitamin parenterally. If there was still no response, the next step would be to give massive doses of thiamine either orally or parenterally. A second type ofcase chosen for study as possibly having a high pyruvic acid was those infants with haenolytic anaemia Sinclair (1939) reported that haenin destroyed thiamine. In a previous paper Allibone and Finch (1945) had found # very low urinary thiamine excretion following successive