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BACKGROUND Inadequate dietary intake of calcium and vitamin D may contribute to the high prevalence of osteoporosis among older persons. METHODS We studied the effects of three years of dietary supplementation with calcium and vitamin D on bone mineral density, biochemical measures of bone metabolism, and the incidence of nonvertebral fractures in 176 men(More)
BACKGROUND Overweight in adults is associated with increased morbidity and mortality. In contrast, the long-term effect of overweight in adolescence on morbidity and mortality is not known. METHODS We studied the relation between overweight and morbidity and mortality in 508 lean or overweight adolescents 13 to 18 years old who participated in the Harvard(More)
OBJECTIVES 1) To establish with nationally representative US data whether menarche occurred earlier in the 1990s than it had 25 years before. 2) To assess whether the occurrence of menarche in relation to weight status and race had changed over this time period. METHODS Relative weight, race, and menarcheal status of girls in the National Health(More)
The longitudinal changes in isokinetic strength of knee and elbow extensors and flexors, muscle mass, physical activity, and health were examined in 120 subjects initially 46 to 78 years old. Sixty-eight women and 52 men were reexamined after 9.7 +/- 1.1 years. The rates of decline in isokinetic strength averaged 14% per decade for knee extensors and 16%(More)
Epidemiologic studies have found a relation between body iron stores and risk of chronic disease. Iron-absorption studies from single meals have shown that many dietary factors can influence nonheme-iron bioavailability. However, little is known about the association of these dietary factors with iron stores in free-living elderly populations. To address(More)
Background. The effectiveness of calcium in retarding bone loss in older postmenopausal women is unclear. Earlier work suggested that the women who were most likely to benefit from calcium supplementation were those with low calcium intakes. Methods. We undertook a double-blind, placebo-controlled, randomized trial to determine the effect of calcium on bone(More)
Vitamin D intake should be sufficient to maintain calcium absorption and prevent increased parathyroid secretion throughout the year. To determine the level of intake that achieved the latter in elderly women, we studied the interrelations among vitamin D intake, serum 25-hydroxyvitamin D (25(OH)D) levels, and parathyroid hormone concentrations in a(More)
Body mass index (BMI) and triceps skinfold thickness (TSF) are commonly used measures of adiposity in clinical and epidemiologic studies. The 85th and 95th percentiles of BMI and TSF are often used operationally to define obesity and superobesity, respectively. Race-specific and population-based 85th and 95th percentiles of BMI and TSF for people aged 6-74(More)
We conducted a study to determine whether increasing vitamin D intake above the recommended dietary allowance (RDA) of 5.0 micrograms (200 IU)/d reduces bone loss in healthy postmenopausal women residing at latitude 42 degrees N. In this double-blind, randomized 2-y trial, we enrolled 247 healthy ambulatory postmenopausal women who consumed an average of(More)
Wintertime declines in vitamin D lead to increased concentrations of parathyroid hormone (PTH) and accelerated bone loss in postmenopausal women. We conducted this study to compare calcidiol (25-hydroxyvitamin D) concentrations of men and women, to examine the influence of season, travel, vitamin D intake, and other variables on these concentrations, and to(More)