CALCIUM AT DIFFERENT AGES IN WOMENS LIFE

The present long life of women raises the problem of prevention agains t osteoporosis. Bone mass formation during adolescence is the first cr itical period, and it might condition the future bone mineral content. Eighty percent of the bone mass is of genetic origin, whereas 20 perc ent depends on the environment (diet, hormones, etc.). Menstrual disor ders may be responsible for bone mineral loss. Pregnancy and breast-fe eding are periods in which calcium requirements increase, yet in all b ut high risk women there are seldom responsible for osteopoenia. The f irst 10 years of menopause constitute a period of exponential bone min eral loss, and this is when oestrogen therapy is most effective agains t bone loss. The usefulness of calcium is still a mater of debate, wit h conflicting results concerning its preventive action on osteoporosis . There seems to be a threshold phenomenon : when normal diet provides a small amount of calcium, calcium supplementation is effective, but beyond a certain level supplementation is thought to be useless. The r esults found in the literature are presented, and the amounts of calci um intakes recommended at different ages are given.