Newsletter

[ Vol. 13 No. 1 ] (January - April 2012 )
Update in pediatric trace elements

W.Frederick Schwenk II
MayoClinic Collegeof Medicine (Untied States)

Goals:

1. To appreciate the importance of selected trace elements.
2. To know significant differences between children and adults with respect to trace elements.

A trace element is an element that constitutes less than 0.01% of total body weight that acts as an integral component of metalloenzymes or a cofactor for enzymes activated by metal ions. The essential trace elements in children, in order of importance, are iron, zinc, copper, fluoride, iodine, selenium, manganese, chromium, cobalt, molybdenum, nickel, silicon and vanadium.

The most common nutritional deficiency in the world is iron deficiency in the world is iron deficiency. Iron is found in hemoglobin and myoglobin, in a number of important enzymes, and in ferritin and hemosiderin. While the relationship between iron deficiency and anemia is well know, recent studies have documented that iron deficiency can give rise to both cognitive and motor defects. The optimal way to give iron to an infant or child dependent upon parenteral nutrition may be through intermittent transfusions.

Zinc deficiency can lead to impaired wound healing, skin changes, anemia, taste changes and growth retardation. Zinc deficiency has been associated with chronic renal disease, preterm infants, cystic fibrosis, inflammatory bowel disease, and sickle cell disease. While concentrations of zinc in breast milk are low, there is enough zinc in breast milk to prevent zinc deficiency in the healthy term infant.

Selenium is important in a number of antioxidant enzymes. Deficiency of selenium can result in macrocytosis, loss of skin and hair pigmentation, and cardiomyopathy. Selenium deficiency has been reported in children receiving long-term parenteral nutrition, in pediatric-aged patients with HIV and in low birth weight infants. Selenium is also being used in infants in neonatal intensive care units to prevent oxidative diseases.

Trace element deficiency sometimes can be difficult to document since the low concentrations in serum are difficult to measure accurately. Standard pediatric trace element formulations available for parenteral use usually only contain zinc, copper, manganese, and chromium. In patients with cholestatic liver disease, careful attention needs to be paid to the concentrations of copper and manganese, while in patients with impaired renal function, the serum concentrations of selenium and chromium may need to be followed.

From  
The 14^th Congress of Parenteral and Enteral Nutrition Society of Asia
“From Nutrition Support to Nutrition Therapy”
October 14-16, 2011, Taipei, Taiwan 
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