695 Serial whole blood B6 vitamer levels in breast, formula and parenterally fed premature infants

Abstract

To assess adequacy of vitamin B6 intake in premature infants, serial blood samples were obtained for vit B6 determination. A 0.5ml sample was frozen, B6 vitamers extracted, separated and quantitated by a HPLC-fluorometric technique. The method measured pyridoxal phosphate (PLP), pyridoxamine phosphate (PMP), pyridoxal (PL), pyridoxine (PN) and pyridoxamine (PM). Multiple blood samples were obtained over a 2-8wk period. Most infants receiving breast milk had low levels of PLP but high PL resulted in total normal B6 levels but some had low total vitamin B6. Several infants receiving formula had marked elevations of PL and PLP -- PL 256ng/ml (Normal=2-8) and PLP 120ng/ml (Normal 6-15). The values decreased to normal with continued feeding. Five infants received total parenteral nutrition (TPN) using commercial solutions for varying causes for 2-6wk period. PL and PLP values increased. Infant I -- PL 941ng/ml whole blood; PLP 293ng/ml. Infant II PL 765ng/ml, PLP 85ng/ml. Infant III PL & PLP beyond measurement. PL & PLP remained high until TPN was terminated. Conclusion: 1) Breastfed infants may have low whole blood PLP levels. 2) Some premature infants receiving proprietary formula have very high blood levels of PL and PLP suggesting an immaturity of B6 degradation. 3) Premature infants receiving TNP develop very high levels of PL and PLP. Commonly used multivitamin solutions used in TPN have excessive amounts of B6 for premature infants.