The effect of oral contraceptive use on vertebral bone mass in pre- and post-menopausal women.

The effects of oral contraceptive use on bone mineral density in pre- and post-menopausal women were evaluated in two separate studies. First, in a population of young women carefully controlled for all risk factors known to be associated with osteoporosis, it was determined that vertebral bone mineral was increased by about 1% for each year of exposure to oral contraceptives. A similar result was obtained by examining vertebral mineral content of an unselected, but healthy premenopausal population. Effects of oral contraceptives on bone mass could not be found among postmenopausal women, unless perhaps in the initial year or two after loss of ovarian function.