Ascorbic acid dynamics in the seriously ill and injured.
BACKGROUND
In addition to the known beneficial effects of ascorbic acid on wound healing and the immune response, it is also a potent extracellular antioxidant. Recent work in septic rats suggests that high-dose ascorbic acid total parenteral nutrition (TPN) supplementation may protect cells from free radical injury and improve survival. In this study, we determined ascorbic acid levels in the immediate post-injury/illness period and evaluated the ability of early short-term high levels of ascorbic acid in TPN to normalize plasma levels.


METHODS
Ascorbic acid levels were determined in 12 critically injured patients and 2 patients with severe surgical infections. Each patient received TPN supplemented with increasing doses of ascorbic acid over a 6-day period. Therapeutic responses were determined by plasma and urine measurements using high-pressure liquid chromatography.


RESULTS
The initial mean +/- SEM baseline plasma ascorbic acid concentration was depressed (0.11 +/- 0.03 mg/dl) and unresponsive following 2 days on 300 mg/day supplementation (0.14 +/- 0.03; P = 1.0) and only approached low normal plasma levels following 2 days on 1000 mg/day (0.32 +/- 0.08; P = 0.36). A significant increase was noted following 2 days on 3000 mg/day (1.2 +/- 0.03; P = 0.005).


CONCLUSIONS
We confirmed extremely low plasma levels of ascorbic acid following trauma and infection. Maximal early repletion of this vitamin requires rapid pool filling early in the post-injury period using supraphysiologic doses for 3 or more days.
Long
C L
CL
Department of Surgery, Carraway Methodist Medical Center, Birmingham, Alabama 32234, USA.
Maull
K I
KI
Krishnan
R S
RS
Laws
H L
HL
Geiger
J W
JW
Borghesi
L
L
Franks
W
W
Lawson
T C
TC
Sauberlich
H E
HE
D000328:Adult; D000975:Antioxidants / Q000378:metabolism / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D001205:Ascorbic Acid / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use* / Q000652:urine; D016638:Critical Illness / Q000628:therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010289:Parenteral Nutrition, Total; D018805:Sepsis / Q000150:complications / Q000378:metabolism* / Q000628:therapy; D013997:Time Factors; D014947:Wounds and Injuries / Q000150:complications / Q000378:metabolism* / Q000628:therapy
D000975:Antioxidants; D001205:Ascorbic Acid