Differing effects of oral conjugated equine estrogen and transdermal estradiol on vitamin D metabolism in postmenopausal women: a 4-year longitudinal study.

Objective: The aim of this study was to examine the effect of either conjugated equine estrogen or transdermal estradiol on vitamin D metabolism in postmenopausal women.

Methods: Twenty-five women from the Kronos Early Estrogen Prevention Study who were randomized to conjugated equine estrogen 0.45 mg/d and 20 women who were treated with transdermal estradiol 50 mg/d (patch replaced weekly) were analyzed in the present study.

The Effect of Dietary Glycemic Properties on Markers of Inflammation, Insulin Resistance, and Body Composition in Postmenopausal American Women: An Ancillary Study from a Multicenter Protein Supplementation Trial.

Controversy exists as to whether high glycemic index/glycemic load (GI/GL) diets increase the risk of chronic inflammation, which has been postulated as a pathogenic intermediary between such diets and age-related alterations in body composition and insulin resistance. We conducted an ancillary study to a randomized, double-blind trial comparing the effects of a whey protein supplement (PRO, = 38) and a maltodextrin supplement (CHO, = 46) on bone density to evaluate the impact of a calibrated increase in GI/GL on inflammation, insulin resistance, and body composition in a healthy aging population. Markers of inflammation, HOMA, body composition, and GI/GL (estimated from 3-day food records) were assessed at baseline and 18 months.

The Effect of a Whey Protein Supplement on Bone Mass in Older Caucasian Adults.

Context: It has been assumed that the increase in urine calcium (Ca) that accompanies an increase in dietary protein was due to increased bone resorption. However, studies using stable Ca isotopes have found that dietary protein increases Ca absorption without increasing bone resorption.

Objective: The objective of the study was to investigate the impact of a moderately high protein diet on bone mineral density (BMD).

Supplementing a low-protein diet with dibasic amino acids increases urinary calcium excretion in young women.

Increasing dietary protein within a physiologic range stimulates intestinal calcium absorption, but it is not known if specific amino acids or dietary protein as a whole are responsible for this effect. Therefore, we selectively supplemented a low-protein (0.7 g/kg) diet with either the calcium-sensing receptor-activating amino acids (CaSR-AAAs) L-tryptophan, L-phenylalanine, and L-histidine, or the dibasic amino acids (DAAs) L-arginine and L-lysine, to achieve intakes comparable to the content of a high-protein diet (2.

Dietary protein-induced increases in urinary calcium are accompanied by similar increases in urinary nitrogen and urinary urea: a controlled clinical trial.

To determine the usefulness of urinary urea as an index of dietary protein intake, 10 postmenopausal women were enrolled in and completed a randomized, double-blind, cross-over feeding trial from September 2008 to May 2010 that compared 10 days of a 45-g whey supplement with 10 days of a 45-g maltodextrin control. Urinary nitrogen, urinary calcium, urinary urea, and bone turnover markers were measured at days 0, 7, and 10. Paired sample t tests, Pearson's correlation statistic, and simple linear regression were used to assess differences between treatments and associations among urinary metabolites.

Inhibiting gastric acid production does not affect intestinal calcium absorption in young, healthy individuals: a randomized, crossover, controlled clinical trial.

Proton pump inhibitors (PPIs) are the most potent gastric acid suppressing drugs available, and their use is widespread. An emerging concern about chronic PPI therapy is whether these drugs impair intestinal calcium absorption, resulting in a negative calcium balance and thereby potentially causing bone loss. The objective of this study was to evaluate the acute effect of the PPI esomeprazole or placebo on intestinal calcium absorption in healthy adults.