Search

Thiamin, thiamin monophosphate, ascorbic acid, and folic acid were determined in serum and cerebrospinal fluid (CSF) in 31 outpatients who underwent a myelography because of back-pain. All subjects were otherwise healthy. The CSF concentration (mean +/- SD) was 8.6 +/- 3.9 nmol thiamin/L, 16.9 +/- 8.3 nmol thiamin monophosphate/L, 133 +/- 58.8 mumol ascorbic acid/L, and 44.9 +/- 13.2 nmol folic acid/L. The CSF-serum ratio was 2.1 +/- 0.8 for thiamin, 8.3 +/- 4.3 for thiamin monophosphate, 3.0 +/- 1.4 for ascorbic acid, and 3.3 +/- 0.8 for folic acid; the amount in CSF was significantly higher than in serum for each compound. These results support the existence of a saturated transport mechanism of water-soluble vitamins from serum into CSF for thiamin monophosphate, ascorbic acid, and folic acid. However, low CSF concentrations are correlated with low serum concentrations for the three vitamins. High serum concentrations should therefore be advocated to ensure high CSF concentrations.

We determined pediatric age-specific normative ranges for total, phosphorylated, and nonphosphorylated thiamin in whole blood (n = 323) and cerebrospinal fluid (CSF; n = 208). Whole-blood total thiamin decreased from 258 +/- 63 (mean +/- SD; age 0-3 mo group) to 214 +/- 44 nmol/L (age 3-12 mo group) in the first year of life and was stable at 187 +/- 39 nmol/L after 12 mo of age. The overall decline in whole-blood total thiamin was mainly due to a drop in phosphorylated thiamin, the biologically active form. Mean CSF total thiamin decreased from 135 +/- 42 (age 0-9-mo group) to 107 +/- 34 nmol/L (age 9-18-mo group) in the first 1.5 y of life and was stable at 84 +/- 51 nmol/L thereafter. This overall decline was due initially to a drop in nonphosphorylated thiamin and later to a drop in phosphorylated thiamin. The changes in whole blood and CSF occurred independently and probably represent metabolic and neurological maturation of the infant. Whole-blood total and phosphorylated thiamin concentrations were lower in blacks only after pubarche. Age-specific norms should be used for determining the thiamin status in infancy because thiamin concentrations are significantly higher in the first few months of life.