Zinc supplementation, mental development and behaviour in low birth weight term infants in northeast Brazil.
OBJECTIVE
To test whether zinc supplementation reduces the deficits in mental development and behaviour that are found in term infants of low birth weight in the study population.


METHODS
A prospective double-blind, part-randomised efficacy trial.


METHODS
A low-income population in Pernambuco, northeast Brazil, where the economy is largely dependent on sugar-cane production, and where over 90% of deliveries occur in health facilities.


METHODS
During a 20-month period, all singleton, term infants weighing 1500-2499 g born to families of low income ( < US $280/month) were enrolled at birth (n = 205). At 6 and 12-months, the numbers tested were 163 and 138 respectively.


METHODS
Infants born from January 1993-January 1994 were randomly assigned to receive daily, except Sundays, a placebo (n = 66) or 1 mg zinc (n = 68). Those born February-August 1994 were given 5 mg zinc (n = 71). Supplementation was for eight weeks, starting at birth. Field workers visited each infant at home to administer the supplement.


RESULTS
At 6 and 12-months, mental and psychomotor development was assessed with the Bayley Scales of Infant Development and no significant differences in the scores of the three groups were found. At 12-months, behaviour was also assessed on 5 ratings. Ratings were highest in infants given 5 mg zinc (P = 0.042).


CONCLUSIONS
Zinc supplementation (5 mg/d) for eight weeks may reverse some of the poor behaviours, particularly responsiveness, exhibited by low birth weight infants. No amelioration of their mental and psychomotor deficits was found.
Ashworth
A
A
Centre for Human Nutrition, London School of Hygiene and Tropical Medicine.
Morris
S S
SS
Lira
P I
PI
Grantham-McGregor
S M
SM
D001519:Behavior; D001938:Brazil; D002657:Child Development; D004311:Double-Blind Method; D006801:Humans; D007223:Infant; D007230:Infant, Low Birth Weight; D008606:Mental Processes; D011203:Poverty; D011446:Prospective Studies; D011597:Psychomotor Performance; D015032:Zinc / Q000008:administration & dosage*
D015032:Zinc