Effect of Zinc and Vitamin A Supplementation on Diarrhea, Physical Growth and Immune Response in Malnourished Children

Condition(s) targeted: Diarrhea; Pneumonia; Acute Respiratory Tract Infection

Intervention: Zinc and vitamin A single dose at enrollment (Drug); Placebo and vitamin A single dose at enrollment (Drug)

Phase: N/A

Status: Completed

Sponsored by: Society for Applied Studies

Official(s) and/or principal investigator(s):
Maharaj K Bhan, MD, Principal Investigator, Affiliation: All India Institute of Medical Sciences, New Delhi
Nita Bhandari, PhD, Principal Investigator, Affiliation: Society for Applied Studies, New Delhi

Zinc deficiency is common in developing country children, as food intakes are often low, foods from animal sources are infrequently used, the bioavailability of zinc from staple cereal-based diets is limited and zinc losses occur during recurring diarrheal illnesses. Zinc deficiency is associated with impairment in immunological and other defenses against infection and increased rates of serious infections. Due to limitations in currently used biochemical markers, supplementation trials in populations likely to be deficient provide a reliable means of assessing health consequences of zinc deficiency.

A significantly lower incidence and prevalence of diarrhea has been observed in zinc supplemented developing country children in several placebo-controlled trials. The effect of routine zinc supplementation on lower respiratory tract infection is still unclear. We, therefore, evaluated the impact of daily zinc supplementation in a representative sample of children aged 6 to 30 months enrolled from a New Delhi slum area, with a sample size sufficient to determine the impact on the incidence of severe diarrhea and acute lower respiratory infection.

Official title: Effect of Zinc and Vitamin A Supplementation on Diarrhea, Physical Growth and Immune Response in Malnourished Children

Study design: Treatment, Randomized, Double-Blind, Placebo Control, Factorial Assignment, Safety/Efficacy Study

Primary outcome:

- To measure the impact of zinc and vitamin A on the duration of diarrheal illness

- To explore whether micronutrient supplementation can decrease the nutritional insult of diarrhea and enhance immune responses to important vaccine antigens

Secondary outcome:

- To measure the impact of supplementation on the outcome of acute diarrhea, particularly on the risk of persistence

- To measure the impact of supplementation on subsequent diarrheal and respiratory morbidity, and physical growth over a 12 week period

- Zinc when administered through household visits and using a programmatically more relevant delivery approach, administration by mothers.

- To measure the impact of supplementation on immune response to parenteral live measles vaccine and oral live tetravalent rotavirus vaccine

Detailed description: Diarrheal disease is a major cause of child mortality in developing countries. Currently, the management of diarrhea focuses on oral rehydration therapy in acute diarrhea. However, acute diarrhea accounts for only 1/3 of the diarrhea-related deaths, the majority of the remaining being caused by persistent diarrhea. Currently persistent diarrhea treatment is complex, not yet adapted to community settings and, hence, has only a marginal impact on diarrheal mortality. A major challenge is to develop and implement cost-effective community-based interventions that can be applied to children with diarrhea to prevent persistence.

The trial was implemented in the urban slum of Dakshinpuri comprising 15,000 dwellings and a population of about 75,000. Recent data from a neighboring community indicated that childhood malnutrition, zinc deficiency, diarrhea and lower respiratory tract infection were common. Children aged 6 to 30 months were identified through a door-to-door survey. Enrollment required that the parents give informed consent and that families did not intend to emigrate. Eligible children were individually randomized by a simple randomization scheme in blocks of 8 generated by a person at Statens Serum Institut, Denmark. The zinc and placebo syrups were prepared and packaged in unbreakable bottles by GK Pharma Aps (Koge, Denmark( and labeled with unique child number according to the randomization scheme. The zinc and placebo syrups were similar in appearance, taste and packaging.

The enrolled children were randomized to receive zinc gluconate (10 mg elemental zinc/day to infants and 20 mg/day to older children) or placebo daily for a period of 4 months. All included subjects were given a massive dose of vitamin A at enrollment in addition to zinc or placebo. A field attendant administered the syrup daily at home for 4 months except on Sundays, when the mother was asked to administer it. One bottle containing 250 mL was kept in the child's home and replaced monthly.

Field workers visited households every seventh day during the 4-month follow-up period. At each visit, information was obtained for the previous 7 days on history of fever, number and consistency of stools. If the child had diarrhea or vomiting, dehydration was assessed. Information was also obtained on cough, lower chest indrawing and o ther illness characteristics and whether teatment wa ssought in the previous 7 days. Intervention impact was assessed on physician-diagnosed acute lower respiratory tract infections and pneumonia.

Minimum age: 6 Months. Maximum age: 30 Months. Gender(s): Both.

Criteria:

Inclusion Criteria:

- Children in the age group 6-30 months

- Either sex

Exclusion Criteria:

- Refused consent

- Likely to move out of study area within the next four months

- Urgent admission to hospital on the enrollment day

- Had received massive dose of vitamin A within the two months before enrollment

All India Institute of Medical Sciences, New Delhi, Delhi 110029, India

Starting date: February 1998
Ending date: September 2000
Last updated: January 2, 2006