Routine L-ascorbic acid supplementation does not alter iron, copper, and zinc balance in low-birth-weight infants fed...

The effect of ascorbic acid (AA) [284 mumol (50 mg) twice daily] on the net intestinal absorption and maximum apparent retention of Fe, Cu, and Zn was investigated by metabolic balance studies in a randomised crossover study of six low-birth-weight (LBW) neonates fed a cows'-milk-based formula containing (mumol/L) Fe, 126; Cu, 11; Zn, 87; and AA, 400. Absorption +/- SD (Fe, -5.0 +/- 7.5; Cu, 0 +/- 0.4; Zn, -0.8 +/- 3.4) (mumol kg-1 day-1) was not altered by AA (Fe, -4.1 +/- 4.6; Cu, 0.3 +/- 0.6; Zn, -1.1 +/- 2.7) neither was retention (without AA: Fe, -6.0 +/- 8.4; Cu, -0.1 +/- 0.3; Zn, -2.4 +/- 4.2; with AA: Fe, -4.9 +/- 4.7; Cu, 0.1 +/- 0.6; and Zn, -2.7 +/- 3.1). Supplements of AA administered as in the circumstances of routine care of LBW neonates do not enhance the absorption and retention of Fe, nor do they impair these aspects of the metabolism of Cu and Zn.