94 research outputs found

    Changes in vitamin-D metabolites and parathyroid hormone in plasma following cholecalciferol administration to pre- and postmenopausal women in the Netherlands in early spring and to postmenopausal women in Curacao

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    To study the effect on plasma 25-hydroxycholecalciferol (25(OH)D), 1, 25-dihydroxycholecalciferol (1, 25(OH)(2)D) and parathyroid hormone (PTH) we supplemented premenopausal (aged 30 (so 7) years) and postmenopausal (aged 61 (so 2) years) white women living in The Netherlands in late winter/early spring, and elderly black and white women (aged 75 (so 6) years) living in Curacao (Dutch Antilles) with either 10 or 20 mu g cholecalciferol/d for 4, 5 and 9 weeks respectively, Baseline plasma 25(OH)D concentration of Dutch women was lower than that of Curacao women, Postmenopausal Dutch women had a higher PTH concentration in plasma than premenopausal Dutch and postmenopausal Curacao women, There were no differences in plasma 1,25(OH),D, Cholecalciferol administration increased 25(OH)D in all groups, 1, 25(OH),D in postmenopausal Curacao women and PTH in postmenopausal Curacao women and premenopausal Dutch women, Serum and urinary Ca and phosphate concentrations did not change, There were no response differences between 10 and 20 mu g doses, Oral cholecalciferol administration (either 10 or 20 mu g/d) to women living at northern latitudes in late winter/early spring increased 25(OH)D levels to the baseline levels of elderly people living in the tropics

    Some Investigations on the Metabolism of Phenylalanine and Tyrosine in Children with Vitamin C Deficiency

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    Scorbutic children excrete some amino-acids in amounts higher than normal in their urine (Jonxis and Huisman, 1954). Serine, threonine, glycine, histidine, lysine, P-amino-isobutyric acid, glutamic acid in bound form and also tyrosine are excreted in increased amounts. It has been known for a number of years that vitamin C is necessary for the normal metabolism of tyrosine. Levine, Gordon and Marples (1941) found that a number of inter-mediates in the metabolism of tyrosine appeared in the urine of premature infants when these infants received a diet high in protein and without vitamin C. The same was found when relatively large amounts of tyrosine or phenylalanine had been added to the food. When vitamin C was given the excretion o
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