Magnesium retention from metabolic-balance studies in female adolescents: impact of race, dietary salt, and calcium.

Background: Previously, we showed that black girls retained more calcium than white girls did and that salt loading negatively affected calcium retention. Racial differences likely exist in other bone minerals also, such as magnesium, in response to salt loading during growth.

Objective: We studied racial differences in magnesium metabolism in response to dietary sodium and calcium during rapid bone growth.

Fructo-oligosaccharides and calcium absorption and retention in adolescent girls.

Background: Several studies have shown a positive effect of fructo-oligosaccharides on calcium absorption and retention in animals and humans. Effects of levels of these pre-biotics that can be functionally incorporated into manufactured foods, have not been studied in controlled feeding studies.

Objectives: This study was designed to evaluate the effect of 9 g/d of fructo-oligosaccharides as part of a controlled diet on calcium absorption and retention in adolescent girls.

Racial differences in potassium homeostasis in response to differences in dietary sodium in girls.

Background: Racial differences in the renal disposition of potassium may be related to mechanisms for the greater susceptibility to hypertension in blacks than in whites.

Objective: Our objective was to study the racial differences in the renin-angiotensin-aldosterone system and in potassium balance in black and white girls consuming a controlled diet that was low in potassium with 2 amounts of sodium intake (low compared with high).

Design: The studies reported here were performed in 40 black and 28 white girls, aged 11-15 y, under highly controlled metabolic conditions.

Racial differences in skeletal calcium retention in adolescent girls with varied controlled calcium intakes.

Background: Higher bone mass in blacks than in whites has been related to greater calcium utilization efficiency. Dietary calcium requirements for maximal skeletal calcium accretion during puberty may differ between the races.

Objective: This study compared the relation between calcium intake and calcium retention in black and white adolescent girls.

Racial differences in calcium retention in response to dietary salt in adolescent girls.

Background: Sodium is an important determinant of urinary calcium excretion, and race is an important determinant of calcium retention. The effect of dietary sodium on calcium retention and the influence of race have not been studied in adolescence, the life stage during which peak bone mass is accrued.

Objective: The study reported here was undertaken to compare racial differences in calcium retention as a function of dietary salt intake.

Sodium retention in black and white female adolescents in response to salt intake.

Increased sodium (Na(+)) retention in blacks could be related to the high prevalence of hypertension in adult blacks. Na(+) retention in response to controlled dietary Na(+) has not been rigorously compared in the different race groups. The present study assessed Na(+) retention in 22 black and 14 white girls, 11-15 yr old, during 3 wk on a low (1.

Comparison of 24 hour whole body versus patch tests for estimating body surface electrolyte losses.

Purpose: To compare dermal electrolyte loss between whole body and regional patch methods in women during 24-h.

Methods: Dermal loss was collected in 6 healthy women mean age 27 +/- 4 years, while consuming 936 mg/d sodium, 1764 mg/d potassium, 696 mg/d calcium, and 152 mg/d magnesium. Twenty-four hour whole body dermal loss was collected using cotton suits by a washdown procedure.