Selenium and breast-feeding

Abstract

The objective of the present review is to discuss Se nutrition during breast-feeding, encompassing environmental and maternal constitutional factors affecting breast-milk-Se metabolism and secretion. A literature search of Medline and Webofscience was used to retrieve and select papers dealing with Se and breast milk. Although Se in natural foods occurs only in organic form, breast milk responds to organic and inorganic Se in supplements. Inorganic Se (selenite, selenate), which is largely used in maternal supplements, is not detectable in breast milk. The mammary-gland regulating mechanism controls the synthesis and secretion of seleno-compounds throughout lactation, with a high total Se level in colostrum that decreases as lactation progresses. Se appears in breast milk as a component of specific seleno-proteins and selenoamino-acids in milk proteins that are well tolerated by breast-fed infants even in high amounts. Se in breast milk occurs as glutathione peroxidase (4 -32 % total Se) . selenocystamine . selenocystine . selenomethionine. The wide range of breast-milk Se concentrations depends on Se consumed in natural foods, which reflects the Se content of the soils where they are grown. Se prophylaxis, either through soil Se fertilization or maternal supplements, is effective in raising breast-milk Se concentration. In spite of wide variation, the median Se concentration from studies worldwide are 26, 18, 15, and 17 mg/l in colostrum (0 -5 d), transitional milk (6 -21 d), mature milk (1 -3 months) and late lactation (.5 months) respectively. Se recommendations for infants are presently not achieved in 30 % of the reported breast-milk Se concentrations; nevertheless Se status is greater in breast-fed than in formula-fed infants.

Blood dynamics of mercury and selenium in northern elephant seals during the lactation period

“…In human milk, worldwide Se values range between 13 and 33 mg/l and variations in levels are mainly due to fluctuations in the Se intake via food (Dumont et al, 2006). A decline of the Se secretion into the human milk also occurs during lactation, especially after the protein-rich colostrum is delivered (Dorea, 2002). Information on Se in marine mammals is limited, but the same dynamics of Se during lactation was shown in pigs (Kim and Mahan, 2001).…”

“…It functions through selenoproteins such as glutathione peroxidase (Dorea, 2002), and protects animals from the toxicity of both inorganic Hg and MeHg (Khan and Wang, 2009). In higher-trophic marine animals, demethylation processes of MeHg are known to occur in the liver with a subsequent formation of HgSe granules (tiemannite), explaining the 1:1 M ratio of Se and Hg observed in these animals (Cuvin-Aralar and Furness, 1991; Koeman et al, 1973;Nigro and Leonzio, 1996).…”

Effects of Antioxidant Supplementation on Duodenal Se-Met Absorption in Ethanol-exposed Rat Offspring In Vivo

“…57, No. 6, 2011 SELENOMETHIONINE ABSORPTION IN DUODENUM OF ETHANOL-EXPOSED RAT OFFSRPING 709 their intestinal development; moreover, our research group has found that Se or Se plus folic acid supplementation during gestation and lactation could prevent liver oxidative damage in the pups, thus improving their development and health [10,11].At present, a limited number of studies have explored Se uptake in offspring rats [16] or infants [17,18], and there are no reports concerning this in ethanol-exposed pups. In this context, Anan et al (2009) [19] found that suckling pups mainly obtained Se presenting in breast-milk in organic form as Se-Met.…”

“…At present, a limited number of studies have explored Se uptake in offspring rats [16] or infants [17,18], and there are no reports concerning this in ethanol-exposed pups. In this context, Anan et al (2009) [19] found that suckling pups mainly obtained Se presenting in breast-milk in organic form as Se-Met.…”

Selenium and Vitamin A and E in the Nutrition of Very Low-Birth Weight Preterm Infants

“…Selenium concentrations in the soil vary in different regions, and the levels in pastures, animals, and human milk follow these regional variations [10]. The major species of selenium in plant sources are selenate (translocated directly from the soil), selenomethionine (SeMet), small amounts of selenocysteine (SeCys) and different seleno-containing proteins [9].…”