Molybdenum requirements in low-birth-weight infants receiving parenteral and enteral nutrition.
BACKGROUND
Molybdenum (Mo) is an essential trace element required by three enzymatic systems, yet there are no reports of Mo deficiency in infants. Low-birth-weight infants (LBW) might be at risk for Mo deficiency because they are born before adequate stores for Mo can be acquired, they have rapid growth requiring increased intakes, and they frequently receive supplemental parenteral nutrition (SPN) and total parenteral nutrition (TPN) unsupplemented with molybdenum.


METHODS
To investigate Mo requirements of LBW infants (n = 16; birth weight, 1336+/-351 g; gestational age, 29.8+/-2.5 weeks; M+/-SD), the authors collected all feeds, urine, and feces prior to TPN (baseline, n = 16, collections = 16), during TPN (n = 9, collections = 19), during SPN (n = 13, collections = 17), and after one week of full oral feeds (FOFs) of formula or human milk (FOF, n = 16, collections = 16).


RESULTS
Infant weights at collection times were: 1.3+/-0.3 g, 1.27+/-0.4 g, 1.4+/-0.3 g, and 1.7+/-0.5 g, respectively. Mo intake was 0.03+/-0.1 microg/d, 0.34+/-0.1 microg/d, 1.25+/-1.7 microg/d, and 6.1+/-2.5 microg/d. Mo output was 0.64+/-0.6, 0.34+/-0.5, 0.68+/-0.8, and 4.1+/-2.5 microg/d. Mo balance at these times was -0.60+/-0.5, -0.001+/-0.5, 0.57+/-1.9, and 2.0+/-2.9 microg/d. Mo balance increased with time, yet some infants were always in negative balance, even though Mo intakes exceeded recommendations.


CONCLUSIONS
The authors speculate that an intravenous intake of 1 microg/kg/d (10 nmol/kg/d) and an oral intake of 4-6 microg/kg/d (40-60 nmol/kg/d) would be adequate for the LBW infant.
Friel
J K
JK
Department of Biochemistry, Memorial University of Newfoundland, Janeway Child Health Centre, St John's, Canada.
MacDonald
A C
AC
Mercer
C N
CN
Belkhode
S L
SL
Downton
G
G
Kwa
P G
PG
Aziz
K
K
Andrews
W L
WL
D004750:Enteral Nutrition; D006801:Humans; D007225:Infant Food; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008895:Milk, Human; D008982:Molybdenum / Q000008:administration & dosage* / Q000378:metabolism; D009751:Nutritional Requirements; D010288:Parenteral Nutrition; D010289:Parenteral Nutrition, Total
D008982:Molybdenum