Factors related to variation in premenopausal bone mineral status: a health promotion approach.

Bone loss prior to menopause may contribute to later risk of fracture due to osteoporosis. Women may be able to optimize premenopausal bone mass and/or prevent losses. Heredity, and possibly age at menarche (retrospectively determined), are unmodifiable risk factors and attention should therefore be directed to more amenable factors. Amenorrhea, low body weight, disordered eating, and smoking are modifiable risk factors. Vitamin D is not a factor for premenopausal women who receive incidental sun exposure and consume fortified foods, but supplementation should be considered for others, especially during the winter months. Protective factors include a higher body weight (especially due to increased muscularity), calcium supplementation, and purposeful load-bearing exercise. Positive effects of oral contraceptives are most apparent in women with menstrual irregularities. Reproductive history (parity), lactation, moderate intakes of alcohol and caffeine, and the appropriate treatment of endometriosis have no apparent effect on premenopausal bone.