Send to

Choose Destination
See comment in PubMed Commons below
Eur J Clin Nutr. 1998 Mar;52(3):223-7.

Zinc supplementation, mental development and behaviour in low birth weight term infants in northeast Brazil.

Author information

Centre for Human Nutrition, London School of Hygiene and Tropical Medicine.



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.


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


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.


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.


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.


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).


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.


Severe zinc deficiency, widespread in developing countries, has been associated with cognitive and psychomotor impairment in animal studies. The capability of zinc supplementation, to reduce the deficits in mental development and behavior found in low-birth-weight term infants, was assessed in a prospective study conducted in a low-income community in Pernambuco, Brazil. All 205 singleton, term infants, delivered at the local hospital in a 20-month period and weighing 1500-2499 g at birth, were enrolled. Infants born from January 1993 to January 1994, were randomly assigned to receive either a placebo (n = 66) or 1 mg of zinc (n = 68) 6 days a week. The 71 low-birth-weight infants delivered from February to August 1994, were given 5 mg of zinc 6 days a week. Supplementation administered by local health workers was initiated at birth and lasted for 8 weeks. Mental and psychomotor development was measured at 6 and 12 months of age by the Bayley Scales of Infant Development. There were no significant differences between infants in the 3 study groups on this test. Also at 12 months, infant behavior was assessed on 5 scales. Ratings for one of these scales (responsiveness to tester) were significantly higher in infants who received 5 mg of zinc than in the 2 other groups, and the 5 mg zinc group also had the highest scores on the 4 other scales. Further studies are urged to investigate the effect of zinc provided later in life, and for longer periods of time, on the development of low-birth-weight infants.

[Indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Loading ...
    Support Center