Anemia and growth abnormalities including stunting and/or underweight in infants aged 0–18 months in rural Shaanxi were still a major public health problem. Some disadvantageous socio-demographic characteristics including poor household, increased sibling number, lower maternal education, crowded living conditions, and low birth weight were significantly associated with anemia. And inappropriate feeding practices were also significantly associated with anemia. Furthermore, there were strong associations between malnutrition (growth abnormalities) and anemia among infants in these rural areas. When we investigated nutritional factors resulting in this issue, we found a special status. That was iron, zinc, and vitamin A deficiencies in serum were not consistent with dietary intake.
China has the largest population in the world with more than 70% of the people living in rural areas [10
]. More than 16 million babies are born in each year since 2000. Although economic and social situations have greatly improved in the past 30 years, health disparities among different regions continue to increase. Malnutrition and associated diseases in children are still very common problems, especially in the remote inland counties [16
]. Shaanxi is a typical inland province in northwestern China. We found that malnutrition and anemia were still very common among 0–18 month-old infants there; the prevalence (47.6%) of anemia in rural infants aged 6–18 months was much higher than in western China (40%) [19
]. This survey used the WHO standard of anemia combined with the Chinese standard for infant <6 months old, which had different cut-off values of hemoglobin for different ages rather a unified hemoglobin cut-off value for all infants [13
]. Our results demonstrated that anemia in 0–18 month-old infants in rural northwestern China was much more prevalent than in New Zealand [20
]. They also indicated that infants from these rural areas were more likely to develop symptoms of malnutrition (growth abnormalities), such as underweight and stunting. The latter is an indicator of chronic malnutrition and is a retardation of linear growth, as measured by total body weight or height, that is the product of a cumulative history of stressful episodes that cannot be compensated by catch-up growth during more favorable periods.
Childhood anemia occurred simultaneously with malnutrition in rural Shaanxi, and >60% showed only mild anemia. This indicated that anemia among these rural infants was potentially associated with malnutrition. Underweight, stunting, and wasting all were risk factors for suffering from anemia [21
Physical development and nutrition status are affected by genetic and environmental factors, as well as the interaction between them [22
]. Environmental factors, especially socio-economic status and feeding habits play leading roles in determining physical development and nutritional status in the early years of life. Risk factors of anemia have been described in a number of studies [23
]. In this population, infants who were born with low birth weight and from lower income family were more likely to suffer from anemia. It had been reported in disadvantaged families from Montreal [26
] that low birth weight was associated with iron deficiency anemia. The multivariate analysis showed the effect of crowded living conditions and more siblings on the prevalence of anemia. The effect had been previously noted by others [27
]. Lack of exclusive or predominant breast-feeding during the first 4 months of life was found to be associated with infant anemia in our study. Prolonged exclusively breasted feeding, such as over 6 months old, was reported to be predictor of infant anemia in developing countries [29
]. The time of starting and the frequency and quality of complementary foods were significantly associated with anemia in this group of infants. So information of introducing proper complementary foods, such as iron-fortified cereal, egg since 4–6 months old should be delivered to mothers and caregivers efficiently. We found less maternal education was one of the risk factors to infant anemia. This risk factor had been identified in rural China [28
]. Given that this was a cross-sectional and retrospective study, we were unable to fully control for recall bias, especially for maternal feeding behavior information. A larger prospective study is required to clarify the causal relationships among these factors with anemia in young children in rural northwestern China.
Accumulating evidence demonstrates that anemia is a common clinical manifestation of micronutrient deficiency, particularly iron, zinc, and vitamin A [21
]. In this study, we investigated the dietary intake levels among 336 infants and serum concentrations of iron, zinc, and retinol (vitamin A) in a subset of 55 infants. Unlike previously published results [21
], We found that lower levels of serum iron, zinc and retinol (vitamin A) concentrations were found among anemic infants. But we didn’t find any differences of dietary intake between anemic and non-anemic infants accordingly. This inconsistency might be due to following explanations. Diet intake was just one determinant factor of nutrient status. The levels of nutrients in blood could be affected by bioavailability or other factors such as genetic influences and physical activity. And some infants were nursing breast milk and complementary foods at the same time. Mineral level of breast milk usually varied greatly between different mothers. On the other hand, these results indicated that other important factors might be involved in serum micronutrient deficiencies [30
]. For example, micronutrient absorption and immune system function might result in serum micronutrient deficiencies. In future studies, we will analyze the status of intestinal microflora and bioactive molecules in serum to attempt to elucidate the causes. Limitations of the present study include: (1) Use of dietary record method for assessment of dietary intake. This method has the advantage of being non-dependant on caregiver’s memory. However, three consecutive days of intake might not be well representative of long term dietary intake of infants. (2) Measuring serum iron alone is not a sensitive indicator for iron status among infants. This was done for financial issues of the study.