Iron Status and Its Associations with Blood and Plasma Divalent Metals among Children Aged 3 to 19 Years Old from Four First Nation Communities in Quebec

Abstract

OBJECTIVES: In First Nations communities, iron deficiency (ID) is a frequent pediatric condition with diverse adverse outcomes. Iron is a divalent metal that share absorptive pathways with cadmium (Ca), cobalt (Co), manganese (Mn), lead (Pb) and zinc (Zn) in the gastrointestinal tract; ID upregulates their uptake and the likelihood of toxic levels in humans. The present study examines associations between ID status, its determinants, and other divalent metals among indigenous youth. METHODS: The 2015 First Nation Youth Environment and Health (JES! -YEH!) pilot study was conducted among children (3 to 19 y, n = 198) from four First Nations communities in Quebec. Blood and urine samples and anthropometric measurements were collected. Serum ferritin (SF), blood Cd, Pb, Mn, Co, plasma Zn urinary cotinine and hs-CRP levels were measured. Determinants (including traditional and market food consumption) were assessed using an interview-administered questionnaire, based on which nutritional intakes were calculated. Descriptive analyses and Structural Equation Models were used to test associations.RESULTS: There was a high prevalence of ID (21.8%). Fruit and juice consumption – via vitamin C intake - were the only food variables positively associated to SF (coefficient [95% CI]: 0.22 [0.11, 0.45]; 0.54 [0.28, 0.80]). Blood Mn was significantly higher than in the Canadian Health Measures Survey. SF was in turn inversely associated to blood Co and Mn (-0.26 [-0.34, -0.19]; -0.15 [-0.20, -0.11]). As a whole, fruits and juice consumption were inversely associated with blood Mn (-0.02 [-0.03, -0.01], -0.04 [-0.08, -0.01]) and Co (-0.03 [-0.06, -0.01], -0.07 [-0.14, -0.02]), via their positive association to vitamin C intake and SF. CONCLUSIONS: Our findings suggest that dietary interventions fostering higher consumption of foods naturally rich in vitamin C, which is known to enhance iron absorption, could decrease ID and ultimately, restore blood Mn and Co homeostasis.