Does zinc help children with diarrhea?

It may help children older than 6 months who live where zinc deficiency or malnutrition is common.^[1] A Cochrane review included 33 trials with 10,841 children. In children older than 6 months, zinc may shorten acute diarrhea by about half a day (low certainty). It probably lowers the number of children still ill on day 7 by 27%.^[1] In children with signs of malnutrition, it shortened diarrhea by about a day.^[1]

In infants younger than 6 months, zinc had no clear effect, and in both age groups it made vomiting more likely.^[1] WHO and UNICEF recommend 20 mg of zinc a day, or 10 mg for infants under 6 months, for 10 to 14 days to treat acute diarrhea in children.^[2] In well-nourished children the effect may be small.^[2]