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 levels was evaluated among children under five years of age living in Mexico City.


METHODS
A random sample of 200 children under five years of age, resident in two neighborhoods of Mexico City was selected: Xalostoc, an industrial neighborhood, and Tlalpan, a residential neighborhood (100 from each area). The mothers of these children filled out a questionnaire on predictors of blood lead levels including daily calcium intake. Lead levels were determined from the venous blood samples. Calcium intake was assessed using a short Food Frequency Questionnaire including 11 food items that accounted for 95% of calcium intake in Mexico.


RESULTS
The average blood lead level was 9.93 microg dl(-1) (range 1-31 microg dl(-1)). An inverse relationship was observed between blood lead levels and daily calcium intake. This relationship was statistically significant among children aged 13 months-5 years.


CONCLUSIONS
The results suggest that calcium provided a protective effect against lead accumulation in the body among children. Further studies should be undertaken to evaluate this hypothesis through experimental design.
Lacasaña
M
M
Center for Population Health Research, National Institute of Public Health, Cuernavaca, Morelos, Mexico. mlacasan@insp3.insp.mx
Romieu
I
I
Sanin
L H
LH
Palazuelos
E
E
Hernandez-Avila
M
M
D002136:Calcium, Dietary / Q000008:administration & dosage*; D002675:Child, Preschool; D006801:Humans; D007223:Infant; D007854:Lead / Q000097:blood*; D016014:Linear Models; D008800:Mexico / Q000453:epidemiology; D012307:Risk Factors; D011795:Surveys and Questionnaires; D014504:Urban Health
D002136:Calcium, Dietary; D007854:Lead