Calcium, Vitamin D Assumptions Shaken

Big Study: They Don't Protect Vs. Most Bone Breaks In Older Women

(CBS)  For women older than 50, federal guidelines recommend 1,200 milligrams of bone-building calcium and 400-600 international units of vitamin D daily from diet and, if needed, supplements.

"The official recommendations are not changing," Senay stressed. "Women who are at especially high risk for osteoporosis need to speak to their doctors not only about vitamin D and calcium supplementation, but also possibly other medications that can help them maintain bone mass or improve bone mass.

"Examine your diet. If you are short on the official recommendations for calcium and vitamin D or calcium, possibly then consider supplementation, again, speaking to your physician. If you are taking it for colorectal cancer prevention, I think the news there is not so good."

The seven-year study of 36,282 women ages 50 to 79 gave half the participants 1,000 milligrams of calcium and 400 units of vitamin D, while the other half took dummy pills.

However, many were also taking their own supplements before the research began, and they were allowed to keep doing so, whether they were assigned to the test group or the comparison group. These extra supplements may have helped the women stay healthy but ironically diluted the findings, since any benefit is harder to show against a backdrop of fewer fractures. Also, women in the study were taking hormone pills, likely further cutting the number of fractures.

The study showed better hip bone density in the group given supplements, but they ranked no better statistically in avoiding fractures of all kinds.

However, some benefit seemed apparent. Women over age 60 reduced their chances of hip fracture by 21 percent with the supplements. And those who took their supplements most regularly lowered their risk by 29 percent.

"There's probably a small benefit," said Dr. Joel Finkelstein, of Massachusetts General Hospital, who wrote an editorial to accompany the study. "It's a good start, but women at higher risk need to know it's not enough."

Many experts downplayed the meaning of the negative finding. Dr. Bess Dawson-Hughes, a Tufts University vitamin expert who helped shape the dietary guidelines, said they should remain unchanged for now.

"You put people who don't need it together with people who aren't taking it, and you find nothing — and that really isn't all that surprising," she said.