Cerebrospinal fluid ascorbic acid levels during the neonatal period.

Corresponding plasma and cerebrospinal fluid ascorbic acid levels were determined in 13 term and 17 preterm newborn infants during the neonatal period. On the first day of life preterm C.S.F ascorbate value of 5.2 +/- 0.8 mg/dl (mean +/- S.E.) was higher than the 3.8 +/- 0.3 mg/dl value in term infants (P less than 0.1). Later determinations during the neonatal period did not demonstrate a difference between term and preterm C.S.F ascorbate values and levelled at 2.9 +/- 0.2 mg/dl. There was a significant negative correlation between the C.S.F/plasma ascorbate ratio and the plasma ascorbate levels and the shape of the regression line was suggestive of a saturable active ascorbate transport from the plasma into the cerebrospinal fluid. Ascorbic acid in the C.S.F of additional six neonates with a neurological disorder was lower than expected on the basis of their plasma levels, the C.S.F/plasma ascorbate ratios being 8.3 +/- 0.9 in the apparently normal infants and 3.7 +/- 0.6 in the neurological patients, (P less than 0.025). The possible mechanism of ascorbate loss from the central nervous system is discussed and it is speculated that ascorbic acid administration following a neurological insult may prove beneficial.