Blood lead levels and calcium intake in Mexico City children under five years of age

Objective: The relationship between daily calcium intake and blood lead lev els was evaluated among children under five years of age living in Mexico C ity. Methods: A random sample of 200 children under five years of age, resi dent in two neighborhoods of Mexico City was selected: Xalostoc, an industr ial neighborhood, and Tlalpan, a residential neighborhood (100 from each ar ea). The mothers of these children filled out a questionnaire on predictors of blood lead levels including daily calcium intake. Lead levels were dete rmined from the venous blood samples. Calcium intake was assessed using a s hort Food Frequency Questionnaire including 11 food items that accounted fo r 95% of calcium intake in Mexico. Results: The average blood lead level wa s 9.93 mug dl(-1) (range 1-31 mug dl(-1)). An inverse relationship was obse rved between blood lead levels and daily calcium intake. This relationship was statistically significant among children aged 13 months - 5 years. Conc lusion: The results suggest that calcium provided a protective effect again st lead accumulation in the body among children. Further studies should be undertaken to evaluate this hypothesis through experimental design.