title: The effect of calcium supplementation on blood lead levels in Nigerian children.
abstract: OBJECTIVE
  To determine whether calcium supplementation alters the risk of lead toxicity.
  
  
  METHODS
  Children aged 12-18 months from 3 communities in Nigeria were assigned to receive daily calcium supplementation, as either calcium carbonate (400 mg) or ground dried fish (529 ± 109 mg), or placebo. All children received 2500 IU of vitamin A. Levels of blood lead, calcium, and vitamin D metabolites were measured at baseline and after 12-18 months (n = 358).
  
  
  RESULTS
  The mean (± SD) baseline lead level was 11.1 ± 7.8 μg/dL (range, 1-43 μg/dL; median, 9 μg/dL); 44.7% of subjects had a lead level >10 μg/dL. After 12-18 months, the mean lead level was 8.1 ± 6.3 μg/dL (range, 1-48 μg/dL; median, 6 μg/dL), with 22.6% with a level >10 μg/dL. Lead levels at baseline varied among communities (P = .01) and were higher in children who used eye cosmetics or lived near a lead-acid battery melter (both P < .001). In a multiple regression model, the decrease in blood lead level was predicted by age, baseline lead level, and time of final lead value at 12-18 months (R(2) = 31%), but not by calcium supplementation (P = .98).
  
  
  CONCLUSIONS
  Lead toxicity is common in Nigerian children, but calcium supplementation does not affect blood lead levels.
authors.affiliation: Mayo Medical School, Rochester, MN, USA. keating.elizabeth@mayo.edu
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Keating
authors.forename: Philip R
authors.initials: PR
authors.lastname: Fischer
authors.forename: John M
authors.initials: JM
authors.lastname: Pettifor
authors.forename: Mark
authors.initials: M
authors.lastname: Pfitzner
authors.forename: Christian O
authors.initials: CO
authors.lastname: Isichei
authors.forename: Tom D
authors.initials: TD
authors.lastname: Thacher
mesh_terms: D000367:Age Factors; D002119:Calcium Carbonate / Q000627:therapeutic use*; D003358:Cosmetics; D019587:Dietary Supplements; D011211:Electric Power Supplies; D005260:Female; D005396:Fish Products; D005526:Food, Formulated; D006801:Humans; D007223:Infant; D007854:Lead / Q000097:blood*; D008297:Male; D015999:Multivariate Analysis; D009549:Nigeria; D012111:Residence Characteristics; D014801:Vitamin A / Q000627:therapeutic use; D014815:Vitamins / Q000627:therapeutic use
chemical_list: D003358:Cosmetics; D014815:Vitamins; D014801:Vitamin A; D007854:Lead; D002119:Calcium Carbonate