A longitudinal study of bone-related biochemical changes at the menopause.

Objective: To evaluate the effects of the menopause on bone-related biochemical variables in a longitudinal study.

Design: Recruitment by advertisement of premenopausal women over the age of 44 for measurement of selected variables and collection of blood and urine samples for deep freezing, followed by annual check of menopausal status and repeat collection of blood and urine samples for deep freezing after the menopausal transition.

Patients: A total of 104 women with confirmed premenopausal status and on no treatment likely to affect calcium or bone metabolism were admitted to the study over a period of 2 years.

Effects of dose and timing of calcium supplementation on bone resorption in early menopausal women.

Bone resorption follows a circadian rhythm that peaks at night, reflecting the circadian rhythm of serum parathyroid hormone. Our previous studies in early postmenopausal women have established that 1000 mg of calcium given at 9 p. m.