Manganese breast milk

Manganese is found in much higher concentrations in infant formulas than in breast milk. In fact, soy-based formulas were shown to contain about 80 times more Mn than breast milk [11]. Also, animal protein-based formulas contained also about 30 times more Mn than human milk. Infants are not able to absorb and excrete excess Mn during their first year of life, a period of rapid development. As Mn is neurotoxic and impairs intestinal Fe absorption, it would be desirable to reduce Mn levels in infant formulas down to those found in human milk (4-8 p,g l-1). Coni et al. [12] reported that in formulas more than 25 percent of total Mn is bound to caseins. On the other hand, Mn present in soy- and in cow s milk-based formula whey is mainly associated with LMW components (< 10 kDa), as is the case with human milk whey [15, 18, 34, 72],... 

One study showed that, in full-term infants, manganese is absorbed from breast milk and cow s milk formulas that were either unsupplemented or supplemented with iron, copper, zinc, and iodine (Domer et al. 1989). Manganese intake was greater in the formula-fed infants than in the breast-fed infants due to the higher manganese content of the formula. However, breast-fed infants retained more of their daily intake of... 

Two studies in suckling rat pups found differing absorptions of manganese from different milks and formulas. The first study (Lonnerdal et al. 1987) found that the percent of Mn (added to the food source as an extrinsic label) retained (measured as whole-body retention) in 14-day-old pups fed breast milk, cow milk, cow milk formula, and soy formula, was 82, 90, 77, and 65%, respectively. 

Manganese is known to cross the placenta and has been detected in cord blood in healthy full-term and preterm infants. It is unknown whether mothers exposed to increased concentrations of manganese will pass on toxic amounts of the metal to their unborn children via the blood. However, as manganese is an essential nutrient and is part of the human body at all times, it is expected to be found in all tissues and fluids of the infant. Manganese is also naturally found in breast milk (typical concentrations in mature milk range from... 

Children would be exposed to manganese in the same manner as adults. The main source of exposure of children to manganese is through food. Infants and young toddlers may be exposed to concentrations higher than the estimated safe and adequate dose for their age group because of the increased levels of the element in infant formulas as compared to breast milk (Collipp et al. 1983 Cook 1997 Dorner et al. 1989 Keen et al. 1986 Lonnerdal et al. 1983, 1994). Manganese concentrations in blood serum of children of different... 

Dorner K, Dziadzka S, Hohn A, et al. 1989. Longitudinal manganese and copper balances in young infants and preterm infants fed on breast-milk and adapted cow s milk formulas. Br J Nutr 61 559-572. 

The upper level of manganese that should be present in infant formula is uncertain, with Hambidge and Krebs [36] proposing an upper limit of 50 p,g/100 kcal (approximately 200 xg/liter) based on toxicity levels however, cow s milk formulas typically contain much more manganese (80-100 xg/liter) than breast milk (6 p.g/liter), and manganese uptake is much greater from the formula [37]. Conclusions here are bedeviled by the fact that the various milks differ not only in... 

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