The Utilization of the Calcium of Dicalcium Phosphate by Children

Kempster, Elizabeth; Breiter, Herta; Mills, R. C.; McKey, Beula V.; Bernds, Marie; Outhouse, Julia

doi:10.1093/jn/20.3.279

Cited by 13 publications

(2 citation statements)

References 14 publications

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“…The same explanation probably covers another observation of Mellanby [1925], namely, that separated milk had some anti-rachitic effect over and above that due to the Ca it contained. It must be admitted, however, that this was a subject of controversy before 1925, and has been ever since [Henry & Kon, 1939;Kempster, Breiter, Mills, McKay, Bernds & Outhouse, 1940]. Adolph & Chen [1932] compared milk and soya bean as sources of Ca to man at two levels of protein intake.…”

Section: Discussionmentioning

confidence: 99%

The Effect of Protein Intake on the Absorption of Calcium and Magnesium

McCance¹,

Widdowson²,

Lehmann³

1943

British Medical Bulletin

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Lehmann & Pollak [1942a] observed that the phosphates and carbonates of Ca and Mg were much more soluble in solutions of oa-amino-acids than they were in pure water, and it has since been shown that the solubility of commercial 'phytin ' can be increased in the same way. In consequence of their observations, Lehmann & Pollak suggested that amino-acids might facilitate the absorption of Ca. To prove or disprove this hypothesis, it was decided to study in human subjects the effect of varying protein consumption upon absorption and excretion of Ca and Mg. Subjects and experimental arrangements There have been five subjects, four men and one woman, and each has carried out two experiments, one at a high level and one at a low level of protein intake. A low protein and a moderately low Ca diet containing fixed rations of milk, 92 % wheatmeal bread, sugar and table fat, was given in both experiments. The rest of the basal diet was made up essentially of potatoes and other vegetables, flavoured and cooked in various ways. The fare varied from day to day during the first experiment, but the menus were repeated exactly during the second. Each person weighed out and ate as much of the vegetable dishes as he or she wished during the first experiment, and adhered to the same amounts during the second. These basal diets, which contained 45-70 g. of protein per day, were supplemented with 100-130 g. of protein (see Table 1) or with an equicalorific ration of sugar or fat. Four different sources of amino-acids were used to widen the scope of the investigation. All the protein supplements contained minerals, and, as far as possible, the intakes of Ca, Mg and P were made equal in the two experiments by administering a salt mixture with the sugar or fat supplement, or, alternatively, by reducing the milk ration when the protein intake was high. One of the protein supplements did not arrive in time to be analysed before the low protein experiment was well under way, and unfortunately in this case the Ca intakes were not equalized. The initials of the subjects, their ages, sex and weights, the duration of their experiments, the nature of their supplements and the * Beit Memorial Fellow.

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Section: Discussionmentioning

confidence: 99%

The Effect of Protein Intake on the Absorption of Calcium and Magnesium

McCance¹,

Widdowson²,

Lehmann³

1943

British Medical Bulletin

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“…Paper (249) is a comprehensive review of many aspects of calcium metabolism by a leading authority on this subject. Inorganic calcium was retained as well as that of milk (396,404,406). Inorganic calcium was retained as well as that of milk (396,404,406).…”

Section: (6) Proteinsmentioning

confidence: 91%

Section D. The Nutritional Value of Milk and Milk Products

Kon

1943

Journal of Dairy Research

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Reviews of the progress of dairy science Thompson (30). Simple rapid methods for the measurement of the yellow colour of milk by means of a 'lactochrometer'(3i) and of carotene in butter fat by visual comparison with potassium bichromate standards (32) have been described. Effern(33) has applied the reaction of Rosenthal & Erdely(34) to the photometric estimation of vitamin A in butter, but the value of this method is not proven and the calculations are open to criticism.In previous reviews (35,36,37) papers dealing with the apparently abnormal behaviour of vitamin A and carotene in butter were discussed, but evidence is now growing that the vitamin A . activity of milk or butter calculated from proper chemical and physical measurements of vitamin A and carotene agrees with results of biological assay (25,38). The recent results of Fraps et al. {39) correcting their earlier findings also point in the same direction, while Shrewsbury & Kraybill(40) now report that carotene dissolved in butter fat devoid of vitamin A activity has the same availability for rats as when dissolved in cotton-seed or maize oil. On the other hand, Koehn(27,28) is still of the opinion that the factor for converting colorimetric readings into international units of vitamin A is appreciably higher for milk than for cod-liver oil.Normally the fat-soluble pigment of milk consists mostly of /? carotene and the ratio of 94 % j8 carotene and 6 % xanthophylls put forward by Gillam(4i) has been generally accepted. It has been known, however, for some time that the exact proportions vary according to the composition of the carotenoids in the fodder of the cow(37). More recent work in which the analysis was done by chromatography instead of by phase separation indicates that even in normal milk the contribution of /3 carotene may be smaller than hitherto believed, while special feeding of the cow may result in the appearance in the milk of much inactive carotenoid. Thus Johnson et al. (42,43) found in the butter of cows receiving molasses lucerne silage only 68 % of the total carotenoids in the form of /} carotene, the rest consisting of xanthophylls, 24 %, and 'acidformed' pigments(44), 8 %. Phosphoric acid lucerne silage yielded 65 % ft carotene and a higher proportion, 12 %, of pigments formed by the action of acid. Even pasture butter had 20 % of xanthophyllic pigments, but artefacts were absent and carotene amounted to 80 % (42,43). Similar values for pasture butters are reported by Thompson et aZ.(45) who also observed that Guernsey cows are less selective than Shorthorns and pass into their milk under comparable conditions a larger proportion of inactive carotenoids. This is doubtless another expression of the known peculiarities of carotenoid metabolism of the Channel Island cattle. There are further examples of these peculiarities. Thus, Gillam & Kon(46) showed that the Shorthorn cow effectively excludes lycopene, an isomer of carotene, from her milk, even when large quantities of it are fed in the form of tomato puree. Under similar...

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