Dietary calcium as a statistical determinant of spinal trabecular bone density in amenorrhoeic and oestrogen-replete athletes.

A study investigating the relationship between spinal trabecular bone density (measured by QCT), dietary calcium (measured by questionnaire) and menstrual status in 67 elite female athletes was undertaken. Twenty-five athletes were amenorrhoeic, 27 eumenorrhoeic and 15 were taking an oral contraceptive. The mean bone density was significantly lower (P less than 0.0001) in the amenorrhoeics (168 mg/cm3; 95% confidence interval 154-182) than in the eumenorrhoeics (211 mg/cm3; 197-224) and oral contraceptive takers (215 mg/cm3; 197-233). There was also a significant positive linear correlation between trabecular bone density. However, factors with which calcium intake may be linked, such as energy intake and expenditure, were not measured and therefore it is possible that this relationship is indirect. Further studies on the relationship between dietary calcium and bone mineral density in young women are needed.