Breast milk containing phosphorus

Phosphorus is found in most foods in concentrations above 100 mg/kg. The exceptions are refined fats and refined sugar, which contain only traces of phosphorus. Nuts, cheeses and other dairy products are rich sources of dietary phosphorus. For cows milk, the ratio of Ca to P is about 1.2 1, while for breast milk the ratio is about 2 1. The absolute amounts of both elements in breast milk compared with cows milk are lower. Many foods of plant origin with high concentrations of phosphorus contain considerable amounts of phytic acid and its salts, phytates, which are not very utilisable. The phosphorus contents in foods are summarised in Table 6.4. 

Sometimes, these effects may be prevented by extra dietary vitamin D, or by exposure to sunlight. However, newborn infants, whose kidneys do not excrete excess phosphate as well as those of older infants and children, may develop high blood levels of phosphate and have seizures when they are fed evaporated milk containing phosphate additives.The seizures are attributed to the fact that cow s milk contains almost four times the calcium and over six times the phosphorus present in human breast milk. Furthermore, extra phosphate is often added to evaporated milk to lengthen its shelf life. Hence, newborn babies fed evaporated milk (diluted with an equal volume of water) may receive between seven and eight times the phosphorus they would get from the same amount of human breast milk. An elevation of the blood level of phosphate causes a corresponding drop in the level of ionized calcium. The direct cause of the milk-induced seizures is the lack of sufficient ionized calcium in the blood. 

Vitamin D Vitamin D enhances the efficiency of the small intestine to absorb calcium and phosphorus from the diet and thus helps to maintain normal serum levels of these minerals. Vitamin D deficiency in infants and children results in inadequate mineralization of the skeleton, causing rickets, which is characterized by various bone deformations. The major source of vitamin D is its formation in the skin as a result of exposure to sunlight. Dietary sources include fortified foods, such as milk and cereals, and certain fish. Infant formula is fortified with vitamin D in many countries. Because human milk contains only low amounts of vitamin D, breast-fed infants who do not receive either supplemental vitamin D or adequate exposure to sunlight are at risk for developing vitamin D deficiency. Subclinical vitamin D deficiency can be assessed by measuring serum 25-hydroxyl-vitamin D deficiency occurs months... 

In the UK, it is recommended that infants who are not breast fed are fed modified milks until at least 6 months of age. These contain less solute, protein, sodium, calcium and phosphorus than cows milk. The Codex Alimentarius lays down international standards for infant feeds Some modified milks are based on demineralised whey and milk to reduce the protein content and change the whey casein ratio examples are given in Table 1. This provides an amino acid composition more closely resembling that of human milk but does not overcome the problem that beta-lactoglobulin and other cows milk proteins are introduced and the anti-infective factors provided by human milk are absent. 

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See also in sourсe #XX -- [ ]

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