CONICET | Buscador de Institutos y Recursos Humanos

The intestine is the only gate for the entry of Ca2+ to the body in humans and mammals. The entrance of Ca2+ occurs via paracellular and intracellular pathways. All steps of the latter pathway are regulated by calcitriol and by other hormones. Dietary and pharmacological compounds also modulate the intestinal Ca2+ absorption process. Among them, dietary calcium and phosphorus are known to alter the lipid and protein composition of the brush border and basolateral membranes and, consequently, the Ca2+ transport. Calcium intakes are below the requirements recommended by health professionals in most countries triggering important health problems. Chronic low Ca2+ intake has been related to ill conditions such as osteoporosis, hypertension, renal lithiasis and incidences of human cancer. Carbohydrates, mainly lactose, and prebiotics have been described as positive modulators of the intestinal Ca2+ absorption. Apparently, high meat proteins increase the intestinal Ca2+ absorption while the effect of dietary lipids remains unclear. Pharmacological compounds such as menadione, DL-butionine-S,R-sulfoximine and ursodeoxycholic acid also modify the intestinal Ca2+ absorption as a consequence of altering the redox state of the epithelial cells. The paracellular pathway of the intestinal Ca2+ absorption is poorly known and is under current study in some laboratories. Another field that needs to be explored more intensively is the influence of the gene-by diet interaction on intestinal Ca2+ absorption. Health professionals should be aware of this knowledge in order to develop nutritional or medical strategies to stimulate the efficiency of intestinal Ca2+ absorption and to prevent diseases.