Many Indonesian infants are already iron deficient before they reach the age of six months, which also determines the high prevalence of anemia among under-five children. Iron deficiency ultimately leads to anemia, and there is clear evidence that iron deficiency anemia during early childhood has a marked negative effect on child development and cognitive function (Lozoff et al.1991; Idjradinata & Pollitt, 1993). This negative impact on childhood development is one of the main reasons why iron deficiency during infancy should be prevented or treated.

Since diets low in iron is usually also low in zinc, zinc deficiency --which has negative consequence on growth-- is common in iron deficiency area. In Southeast Asia, the condition is exacerbated by the rich phytate content in the complementary foods which inhibits the absorption of iron as well as zinc (Gibson, 1994). Thus, combining both iron and zinc, hence, is expected to decrease both iron and zinc deficiencies and hence improve growth and development of the children.

Recently, there has been an emerging view which looks at the two-way relationship between nutrition, health, and psychosocial well-being. This concept is supported by studies on "positive deviance", a term used to refer to children who grow and develop well in impoverished environments where most children are victims of malnutrition and chronic illness (Zeitlin et al., 1990). The mechanism which helps to explain how psychosocial factors, such as the affect between mother and child, are associated with adequate growth and development: 'Psychological stress has a negative effect on the use of nutrients whereas psychological well-being stimulates the secretion of growth-promoting hormones. Pleasantly stimulating interactions can enhance the child's tendency to exercise its developing organ systems and hence to utilize nutrients for growth and development'.

Understanding how the psychosocial environment can promote or inhibit the benefit of supplementation intervention is necessary in order to have a better way of setting about providing supplements. In fact, many supplementation programs do not incorporate complementary program elements that would help to improve the health and psychosocial development of children at the same time that they improve nutritional status' (Myers, 1995). Looking from this perspective, not only will supplementation benefit the psychosocial development but also the psychosocial environment can promote the benefit of the supplementation on the nutritional status and developmental outcomes of infants.

The purpose of the study is to investigate whether multi-micronutrient supplementations (zinc+iron, zinc+iron+vit.A) have positive effect on infants' growth and developmental outcomes, and whether the effect is modified by psychosocial care.

Inclusion Criteria:

• 3 to 6 month old
• predominantly breast-fed children (assuming the infants were already introduced complementary feedings as early as 4 months)
• parental consent

Exclusion Criteria:

• apparent congenital abnormalities