Fortification of milk with calcium: effect on calcium bioavailability and interactions with iron and zinc.
Calcium solubility, dialysability, and transport and uptake (retention + transport) by Caco-2 cells as indicators of calcium bioavailability have been estimated in the in vitro gastrointestinal digests of milk and calcium fortified milk. A significant linear correlation (p < 0.05) was obtained between calcium uptake and the amount of soluble calcium added to the cells, and also between percentage calcium uptake and the calcium measured in the analyzed samples. The solubility, dialysis, transport, and uptake values are higher (p < 0.05) for calcium fortified milks than for nonfortified milks; that is, calcium fortification increases not only calcium content but also its bioavailability. An inhibitory effect of calcium from fortified milks upon iron absorption was found. The observed effect of calcium from fortified milks upon zinc bioavailability depends on the in vitro method used, zinc solubility and dialysis decrease in calcium fortified milks, and percentage zinc uptake remains unchanged.
Perales
Sara
S
Nutrition and Food Chemistry, Faculty of Pharmacy, University of Valencia, Avda. Vicente Andrés Estellés s/n, 46100 Burjassot, Valencia, Spain.
Barberá
Reyes
R
Lagarda
María Jesús
MJ
Farré
Rosaura
R
D000818:Animals; D001682:Biological Availability; D001692:Biological Transport; D002118:Calcium / Q000032:analysis* / Q000493:pharmacokinetics* / Q000494:pharmacology; D004347:Drug Interactions; D005527:Food, Fortified; D007501:Iron / Q000032:analysis / Q000493:pharmacokinetics*; D008892:Milk / Q000737:chemistry*; D012995:Solubility; D015032:Zinc / Q000032:analysis / Q000493:pharmacokinetics*
D007501:Iron; D015032:Zinc; D002118:Calcium