Role of Zinc in Physical Growth and Cognitive Development

Role of Zinc in Physical Growth and Cognitive Development Summary The study covered 2 to 3 year old children in Laguna, Philippines. The study was conducted for the following purposes: to determine the zinc status and its relationship to physical growth and cognitive development; to describe the socio-economic and demographic characteristics, water and sanitation practices, health services, and child care and feeding practices of mothers; to evaluate the food intake and nutrient adequacy; to assess the nutritional status, zinc status and iron status; to determine the level of cognitive development; and to examine the association of zinc status with water and sanitation practices, health services, child care and feeding practices, nutritional status, iron status, and cognitive development. Socio-economic and demographic characteristics revealed that more than half of the households were located in lowland areas. Majority were living in single houses. Some owned the house and inherited the lot from parent. In terms of house materials, most roofs and external walls were made from galvanized iron and concrete/brick/stone. More than one-third of the households have floorings cemented with tiles/linoleum. The main source of electricity was MERALCO in which more than half have their own electric meter. LPG was their major source of fuel for cooking. Further, few households have small holding with agricultural animals like cattle, chicken, ducks, horses and milk cows. Of the households, 69% have 3 to 5 members in the family and 38.5% have children 12 years old and below. In terms of household income, the monthly income ranges from Php1, 000.00 to Php67, 200.00 with a mean monthly income of Php7, 762.00. In general, 57.7% of households were below poverty threshold. The age of mothers ranged from 19 to 58 years old. With a mean age of 29.9 years, more than one-third of the mother-respondents were between 25 to 29 years old. Nearly 3% and 25% were below 20 years and beyond 35 years of age, respectively. In terms of education attainment, majority of mother-respondents either reached high school or graduated from high school. Probably because of lack of education, majority of them have no occupation. Majority of the mothers were married. With regards to religion, most mothers were Roman Catholic. There were more children in district 2 who participated in the study probably because of higher number of children in the area. More than half were 31 to 35 months of age and were female. Some of them belong as the second child in the family. Moreover, 30.2% of the mothers remembered the birth weight of their children based from recall and as recorded in the child’s birth certificate. Only 4% of children were born with low weight. More than one-third of the households have main source of and access to drinking water from the community water system. More than half of the mothers stockpiled water in plastic containers with cover for less than 5 days which can reduce the risk of water storage from being contaminated. Perhaps having an access to sufficient quality and quantity of safe water for consumption, nearly one-third of the mothers do not to store water for drinking. Majority of the mothers spent amount of time obtaining water from water sites that could have been dedicated to other activities like child care. In terms of toilet facilities, almost all households have their own water-sealed latrines however 30.9% of them shared their toilets with other households. In relation to garbage disposal and segregation, most of the households have their garbage collected and carried out proper waste segregation possibly because of the garbage collection system being implemented in the province. In terms of health conditions, almost 70% of the children have been sick for the last 30 days. The most common type of illness experienced was Upper Respiratory Tract Infection such as cough, cold and pneumonia. Parasitism was one of the existing health illnesses among children but majority of them were not yet dewormed. Among children who had suffered from illnesses, 85.9% of the mothers sought for medical help probably because of better access to health centers. In terms of infection, only 12.1% of children were tested positive with infection. Male children were more at risk to infection than female counterparts. With regards to health services, 48.3% of children were not fully immunized, 20.1% received iron syrups and 79.2% received Vitamin A supplementation. More than half of the mothers brought their children to health centers when suffering from diarrhea and nearly 30% of children were provided with Oral Rehydration Solution (ORS). In terms of participation in nutrition educati on classes, only 32.2% of the mothers were attending. In addition, 65.1% of the households were involved in different government nutrition programs food fortification, food assistance, community food production and livelihood programs. Relative to child care and feeding practices, most of the mothers were the main source of physical and emotional care of the children. In her absence, 31.6% of grandmothers took responsibility by feeding the child, bathing the child and baby-sitting. All mothers claimed that they frequently talk, praise, kiss/hug/show affection, play, and tell stories with their children. During meals, majority of the mothers help, encourage and motivate the children to eat as well as they maintain eye to eye contact and minimize distractions if children lose interest easily. Similarly, most of the mothers put their children to sleep and take care of them when they wake up at night. In terms of the children’s personal hygiene, more than half of them have their own utensils. Majority of children’s hands and face were being washed before eating and after toileting. Of the mothers, almost all wash their hands after toileting the child. In relation to the cleanliness of environment, most of the mothers made sure that their children do not eat food picked up from the ground, do not eat food touched by animals and keep their children away from animal excrement. Moreover, most of the mothers exclusively breastfed their children; initiated breastfeeding within the first hour of life; and gave colostrum during infancy. Nearly half of the children were introduced with solid foods at six months. Most of the children were continued being breastfed by mothers even when they have been given solid food. As children grow old, almost all mothers said they increase their children’s quantity of food, frequency of feeding, consistency of food, and number of food given to them. Moreover, nearly all mothers experiment food combinations, tastes and textures for their children. Similarly, majority of the mothers feed their children during illnesses and recovery. In reference from the scoring system developed for the study, results show that child care and feeding practices of the mothers were excellent which may be attributed to participation in health and nutrition education activities conducted in every barangay. Feeding problems were being encountered among children. Majority of the children accept very limited number of food and reject other food thus they eat food of the same nutrients. Most of them tend to linger with their food during mealtime. More than half eat more than what they need. Conversely, a few of them felt like vomiting especially when fed with coarse foods and some asserted independence in choosing the taste of food. The mean 2-day total food intake of children weighed 1126.2 grams. The two food items considered as the most important in children’s diet were rice and rice products, and whole milk. Overall, majority of the children had energy intake of 100% or more and protein intake of 80% or more. More than 80% of children were able to meet the EAR for Fe and 79.2% for Zn. Thus, no elevated risk of zinc deficiency was found among children based on zinc intake. In terms of supplementation, results show that 47% of children were given with vitamin supplements. Based from the three anthropometric indices, weight-for-age showed that 81.2% of the children had normal weight-for-age while 18.8% suffered from acute malnutrition. Disaggregating by gender, females were more at-risk to acute malnutrition than males. Height-for-age revealed that 33.5% of children were stunted while 66.4% of children had normal height-for-age. The distribution of height-for-age by gender revealed that males had higher prevalence at 19.5% than females. Weight-for-height presented that 3.4% of children had low weight-for-height. Majority had normal weight-for-height while 1.3% was overweight-for-height. Considering the weight-for-height distribution by gender, the current nutritional status of children revealed that 45.6% and 49.7% males and females, respectively, had normal weight-for-height. In terms of biochemical indices, the overall zinc deficiency prevalence was 2%, which considered as low public health significance. The mean serum zinc level in children was 123. 13Â µg/dL. Both gender had the same mean serum zinc, but female children were found at risk to zinc deficiency. The overall anemia prevalence rate was 12.1% and considered as moderate public health significance. The mean hemoglobin level of children was 11.95 g/dL. Mean hemoglobin level and prevalence was higher among female children than male. Only 12.1% of children were tested positive with infection. Male children were at risk to infection than female counterparts. Assessment of cognitive development showed that the average cognitive scaled score was 9.72 points. Disaggregated by age in months, 31 to 35 month old children had the highest average cognitive scaled scores. In general, 27.5% of children were delayed in overall development, from which 12.1% had significant delay while 26.2% were advanced in their overall development from which 1.3% was significantly advanced. Correlation analysis revealed that significant associations were found in water and sanitation practices, health services, infection, food intake, nutritional status and cognitive development. No association was found between child care practices and nutritional status. Using the regression model, the study showed contributory factors that zinc status were energy intake, iron intake, zinc intake, height-for-age, cognitive development and infection. Conclusions The study imparted some knowledge and understanding on the association of zinc status, physical growth, other biochemical indices and cognitive development. It provided evidences on the association of zinc status with water and sanitation practices, infection and health services, child care and feeding practices, food intake, physical growth, iron status and cognitive development. The study found factors that were associated with nutritional status of children. Water and sanitation practices of the households and the mothers like sources of water, storage of water, garbage disposal and waste segregation as well as health services extended to children were associated with nutritional status. In the same manner, infection, food intake and cognitive development were associated with nutritional status. Similarly, weight-for-age, height-for-age and weight-for-height were associated with zinc status, iron status and cognitive development. Associations were found in zinc status, iron status and cognitive development and between iron status and cognitive development, as well. Regression model showed the contributory factors that may affect zinc deficiency. Children with adequate intake of energy, zinc and iron were less likely to become zinc deficient. Similarly, zinc deficiency was less likely to occur among children with normal height for their age and who have an average cognitive development. Conversely, zinc deficiency was higher in children with infection. Recommendations With the assessment of zinc status and its relationship with physical growth and cognitive development, it is recommended that in the achievement of optimum nutritional status of 2 to 3 year old children, food intake should be improved early in life. Nutrition counselling among mothers on Infant and Young Child Feeding should be implemented to promote breastfeeding; the importance of early initiation of breastfeeding and timely introduction of complementary feeding; and its effect on infant growth and survival. Considering the new child growth standards, promotion of breastfeeding and improvement of appropriate complementary feeding are important due to its effects on morbidity, feeding patterns and growth outcomes beyond infancy. Similarly, exclusively breastfed infants of mothers with adequate zinc nutriture can provide their zinc requirements up to 5 to 6 months in life. However, after 6 months of age, breastmilk alone cannot supply sufficient zinc to meet infant’s needs. S o, delayed introduction of complementary foods until after 6 months of age, or inadequate amounts of absorbable zinc in complementary foods increased the risk of zinc deficiency. Therefore, ensure messages on zinc that presented to have associations with stunting and cognitive development. These nutritional outcomes are important in the overall growth and development of children. Because stunting is irreversible after 36 months of age, interventions on pregnant women and young children, particularly those under 24 months of age, should be given attention. Supplementary feeding interventions beyond 36 months of age would not reduce stunting, as rapid weight gain in later childhood is associated with adverse long-term outcomes. A preventive strategy of behavioural change communication for mothers and food supplementation for all 6 to 23 month old children should be targeted in conjunction with the content and timing of present nutrition interventions. In the Philippines, zinc supplementation is provided for the treatment of diarrhea. The study had recognized that zinc delivery intervention such as supplementation improves zinc status, physical growth and cognitive development, as well as documented in the Lancet Series 2013. Health service providers should examine the existing policies on micronutrient supplementation and consider if zinc supplementation could be integrated in the program. Mothers’ participation in health and nutrition services and programs improved the nutritional status of children. Thus, the local health units and health service providers should encourage the participation of the mothers in all health services such as immunization, deworming and micronutrient supplementation. The implementation of micronutrient supplementation should be properly strategized and improved. Health service providers should be more competent and more responsive. Supplies should be continuously available. Health information system should be more efficient and client care should be organized. Government programs should be intensified as these contribute to the improvement of nutritional status. Proper targeting of households and individuals should be designed especially when resources are inadequate. Moreover, nutrition programs should be periodically monitored to review the information, implementation and coverage and use for comparison with the implementation plans. Similarly, programs should be systematically and objectively evaluated to measure the relevance, efficiency and cost-effectiveness; to determine if needs and results have been or are being achieved, and to analyze the details for any discrepancy.