.A LARGE, seven year study of healthy women over 50 found no broad benefit from calcium & vitamin D
supplements .
The study, whose results found no evidence that the
supplements prevented colorectal cancer, & it found an increased risk of kidney stones. The study's leaders said there were hints of benefits for some subgroups in the study. But the supplements' only positive effect in the overall study
population-----36,282 normal, healthy women ages 50 to 79 ---------was a 1 per cent increase in bone density at the hip. The $18 million study was part of the women's Health Initiative , large federal project whose results have confounded some popular beliefs and raised questions about public health messages that had been addressed to the entire population. The survey report finds that low fat diets do not protect against breast or colorectal or heart disease.A few years ago, the initiative's study on hormone treatment after menopause showed it had more health risk than benefits.In every case, the initiative was testing hypotheses that arose from studies that observed populations and correlated certain health practices with medical outcomes . But such observational studies , statisticians agree, can yield misleading information because a group that happens to follow certain health advice may differ.