Obesity and micronutrient status predict inflammation and weaker immune function in Filipino schoolchildren

The study examined the association of nutritional status (i.e., anthropometric and micronutrient status) with infection, inflammation, and immune cell quantities in 166 apparently healthy Filipino children aged 5–9 years attending public schools in Manila. Children with low, normal, and high body mass index (BMI)-for-age were compared in terms of micronutrient status (iron, vitamin D, vitamin C, and riboflavin), Epstein–Barr virus (EBV) infection, inflammation, and immune cell quantities. Micronutrients contributing to the variance in inflammation and abnormal immune cell quantities were identified. Inflammation and poorer immune health (characterized by high C-reactive protein (CRP) and low neutrophils, respectively) were more prevalent in children with overweight and obese BMI-for-age than in those with either normal or low BMI. Previous EBV infection was found in 88.7% of children. After controlling for infection, low level of serum vitamin C predicted inflammation, while increased level of iron (hemoglobin) in the presence of vitamin C predicted an abnormal neutrophil level, occurring mostly as neutropenia. Viral infection, overweight, and obesity adversely affect Filipino children’s immune health. Increases in the level of iron (hemoglobin) further impair immune function by providing the iron needed for viral proliferation. The Philippine government requires mandatory iron fortification of staple foods and voluntary iron fortification of processed foods. Given the high prevalence of EBV infection and rising obesity among children, iron fortification policies should be reexamined to ensure that iron is used solely to address iron-deficiency anemia rather than to promote the development of EBV-associated malignancies or other infections. Instead, the policies should focus on increasing vitamin C intake from fresh fruits and vegetables to improve child immunity.