The exact mechanism for the decrease in intestinal calcium absorption with age is not yet
understood. A decrease with age in serum 1, 25‐dihydroxyvitamin D (1, 25 (OH) 2D) or a …

Recent reports of increases in serum 1, 25-dihydroxyvitamin D [1, 25 (OH 2) D]
concentration with aging despite no changes or decreases in calcium absorption suggest …

Intestinal calcium absorption assessed by a double-isotope method, decreased significantly
with aging in 94 normal subjects (r=− 0.22, P< 0.025). In 52 untreated patients with …

We studied the mechanism of impaired calcium absorption with aging in 51 healthy women
whose ages ranged from 26 to 88 years. Serum concentrations of 1, 25‐dihydroxyvitamin D …

Although aged rats reportedly have reduced intestinal vitamin D receptor (VDR)
concentrations, it is unclear whether an analogous age-related defect occurs in man. Thus …

Background: Vitamin D sufficiency may be determined by the serum concentration of 25-
hydroxyvitamin D [25 (OH) D] that results in maximal intestinal calcium absorption efficiency …

Background: The relative importance of vitamin D metabolites in the regulation of gut
calcium absorption has not been well studied in elderly women living in an environment with …

Intestinal calcium absorption decreases with aging, but it is unclear whether this is
attributable to an age-related intestinal resistance to 1, 25-dihydroxyvitamin D [1, 25 (OH) …

Vitamin D deficiency, which causes osteomalacia, may also be important in the
pathogenesis of age-related osteoporosis. We studied serum vitamin D metabolites in 52 …

To examine putative sources of interindividual variation in calcium absorption efficiency, we
studied 41 healthy premenopausal women (mean age, 36.4 yr). About half were randomized …