20 August 2011


Acute diarrhea remains one of the leading causes of death in children throughout the world.  Nearly two million children die each year, mainly in developing countries.  Half of these deaths are exacerbated by acute and chronic malnutrition.  We need to look no further than our TV screen to see the dire effects of this lethal combination unfolding in Somalia and Sudan.  In recent years a multitude of studies have shown a substantial benefit of zinc supplementation in reducing severity, duration and mortality in infants and children with diarrheal disease.  This benefit is most marked in areas where on-going zinc deficiency is prevalent.  Some localities report an incidence of 75% or greater.  Contributing factors include inadequate dietary intake, excessive losses because of diarrhea, and decreased intestinal uptake of zinc, usually caused by chronic diarrhea.
Zinc deficiency causes a destabilization of cell membranes and disrupts the mucosal lining of the intestinal tract. This effect increases the severity and duration of diarrhea.  Zinc deficiency also causes impairment of immune function and a delay in wound healing.  Chronic deficiency can also cause a stunting of growth.
On the basis of many studies over the past decade, the World Health Organization has recommended that a supplement of zinc be administered to every infant and child with acute or chronic diarrhea who is at risk for zinc deficiency.  The dose is 10-20 mg of elemental zinc (usually given as zinc sulfate or acetate), once or twice daily for the duration of the diarrhea.  
Administration is particularly critical if the child is malnourished.  Occasional increase in vomiting is the only observed side effect.  Zinc sulfate is widely available in liquid or tablets, and is very inexpensive. (1)  Some question has arisen as to whether infants under 6 months of age, in particular those who are exclusively breast-fed, will benefit from zinc supplementation.   Breast milk is a reliable source of dietary zinc, but may not be enough to counter the increased losses associated with diarrhea. (2).   A recent WHO report showed a definite benefit of zinc in infants from 2-6 months of age, and recommends its routine use in this age group. (1)
The evidence is overwhelming that administration of zinc should be a routine component of treatment for children with diarrhea in developing countries.
  1. Mazunder et. Al.  Effectiveness of Zinc Supplementation plus Oral Rehydration Salts for Infants Aged Less Than Six Months in Haryana State India.  Bull WHO 88:754, 2010.
  2. Fischer Walker, C et. Al.  Zinc Supplementation for the Treatment of Diarrhea in Infants in Pakistan, India and Ethiopia.  Journal of Pediatric Gastroenterology and Nutrition 43:357, 2006.
Submitted by Roger Boe MD

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