The effect of zinc-supplemented bread consumption on school children with asymptomatic zinc deficiency

J Pediatr Gastroenterol Nutr. 1998 Feb;26(2):167-71. doi: 10.1097/00005176-199802000-00008.


Background: Zinc deficiency has been seen in developing countries in which grain-based vegetable protein is consumed more often than animal protein. This study was done to emphasize the importance of zinc-fortified foods and to investigate bioavailability of zinc in zinc-fortified bread.

Methods: Serum zinc concentrations in healthy 7- to 11-year-old school children were determined. In 24 of 101 children serum zinc concentrations were below 65 micrograms/ul. These 24 children with asymptomatic zinc deficiency were divided into two equal groups. The 12 children with low serum zinc concentrations received the zinc-fortified bread providing 2 mg/kg/day elemental zinc acetate for 90 days (zinc-supplemented group), whereas the other 12 children received the same quality bread with no zinc fortification (control group).

Results: By the end of the period, the zinc-supplemented group had significantly higher serum and leukocyte zinc concentrations (p < 0.01) and the weight, serum albumin levels, and alkaline phosphatase increased (p < 0.01). Immune functions improved, evidenced by conversion of delayed hypersensitivity skin reactions. Zinc-fortified bread (2 mg/kg/day) caused no side effects or manifestations of zinc toxicity.

Conclusions: The results indicate that the bioavailability of zinc in the bread is satisfactory. The use of zinc-fortified bread was found to be an economical and readily accessible method to eliminate zinc deficiency and to prevent further occurrence.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Alkaline Phosphatase / blood
  • Antigens, Fungal / immunology
  • Biological Availability
  • Bread*
  • Candida / immunology
  • Child
  • Female
  • Food Services
  • Food, Fortified*
  • Humans
  • Hypersensitivity, Delayed
  • Male
  • Schools
  • Serum Albumin / metabolism
  • Turkey
  • Zinc / administration & dosage*
  • Zinc / deficiency*
  • Zinc / pharmacokinetics


  • Antigens, Fungal
  • Serum Albumin
  • Alkaline Phosphatase
  • Zinc