Perinatal and infant nutrition. Nucleotides.

Nucleotides (NT) are ubiquitous intracellular compounds of crucial importance to cellular function and metabolism. Much recent interest has focused on NT as components of the non-protein nitrogen fraction of human milk. NT supplementation of infant formula has now been introduced in several countries. Biological effects of NT have been reported in several fields. Dietary NT have been shown to have important effects on several components of the immune system: they may enhance intestinal absorption of iron; they affect lipoprotein and long-chain polyunsaturated fatty acid metabolism; they may alter intestinal flora; and they have been demonstrated to have trophic effects on the intestinal mucosa and liver in several experimental situations. Clinical studies have shown NT supplementation of infant formula reduces the incidence of diarrheal episodes among socioeconomically deprived infants, and enhances catch-up growth in infants born small for gestational age. Further work will continue to try to identify other clinical situations in which NT may have a beneficial role.