Bone Density After Menopause

New study parts with prior recommendation against calcium and vitamin D for women past menopause

(RxWiki News) Maintaining strong bones as we age helps ensure a certain level of mobility and physical independence. Post-menopausal women whose bones might be prone to getting weaker and thinner often are scouting remedies to that.

Questions of which remedies, if any, might be the best are a continuing source of debate.

A new study, nevertheless, has concluded that post-menopausal women who take calcium and vitamin D supplements, plus therapeutic hormones for menopause symptoms, may suffer fewer hip fractures.

"Ask your doctor about taking vitamins after menopause."

John A. Robbins, MD, an internal medicine and geriatric medicine physician at the University of California at Davis Health Systems, was the study's main author.

Dr. Robbins and colleagues investigated the health records of roughly 36,000 post-menopausal women enrolled in the Women's Health Initiative clinical trials for hormone therapy between 1993 and 1998. They ranged in age from 50 to 79. 

They compared the risks of hip fractures in several groups of women: 

  • Those taking 1,000 milligrams daily of calcium and 400 international units a day of vitamin D, along with therapeutic hormones.
  • Those taking only hormones.
  • Those taking only the supplements.
  • Those taking no hormones and no supplements.
  • Those taking only placebos with no medicinal value.

The researchers found the follow rates of hip fractures:

  • 11 hip fractures per year for every 10,000 women who took hormones and supplements 
  • 18 hip fractures per year per 10,000 women taking only hormones
  • 25 hip fractures per year per 10,000 women taking supplements alone
  • 22 hip fractures per year per 10,000 women who did not take supplements nor hormones

Or, stated another way, women taking hormones, along with calcium and vitamin D, were about half as likely to fracture their hips than women taking no hormones or supplements. 

In a press release announcing the study, the researchers were quoted as saying that their findings were different from a US Preventive Services Task Force recommendation issued earlier this year.

According to its own February 2013 announcement, the task force "...found that the current evidence is insufficient to make a recommendation on daily supplements greater than 400 [international units] of vitamin [D] and greater than 1,000 [milligrams] of calcium for the prevention of fractures in post-menopausal women."

"These results suggest that women taking post-menopausal hormone therapy should also take supplemental calcium and vitamin D," the researchers wrote. 

The researchers did not specify supplemental dosages of calcium and vitamin D. They did conclude that the benefits of those supplements noted seemed to increase as the intake of calcium and vitamin D increased. 

They said the dosages should be determined by how much of the supplements individual women can take without developing intolerable levels of constipation and other side effects associated with these supplements.

"The supplements and hormones had a synergistic effect," the researchers wrote. "Women using both therapies had much greater protection against hip fractures than with either therapy alone. Taking supplements alone wasn't significantly better than taking no supplements and no hormones. 

"The benefit of hormone therapy was strong in women who had a total calcium intake [from supplements and food they ate] greater than 1,200 [milligrams per day]. Similarly, the benefit was strong in women who had higher intakes of vitamin D. But the individual effect of each one could not be determined because the two supplements were given together," they wrote.

Ronald de la Pena, MD, a Thousand Oaks, CA gynecologist whose specialties include menopause care, said the study rightly notes that osteoporosis, or the weakening of bones, is a serious condition. It generally is not cured by diet and exercise alone, he said.

Pena told dailyRX that he has "looked at osteoporosis care like building a three-legged stool. Each leg is necessary or the stool doesn't work.  First, [the patient] needs activity with weight-bearing exercise. Second, [she needs] adequate calcium plus vitamin D supplementation, and, lastly, medicine.  Most gynecologists have a good understanding of osteoporosis and will be an excellent resource for their patients." 

Specifically, the researchers investigated the supplement and hormone intake – or lack of intake – of 36,000 women in those clinical trials.

They divided the 36,000 almost evenly into two groups. The first group of 18,000 women took 1,000 milligrams daily of supplemental calcium and 400 international units a day of vitamin D. Of that 18,000, about 4,000 were on hormone pills and 4,000 were taking pills that looked like hormone pills but actually were placebos with no medicinal properties. The remaining 10,000 women in that group did not take hormones or hormone look-alike placebos.

A second group of 18,000 women took placebos daily that looked like the calcium and vitamin D supplements. Of that group taking the placebos, 4,000 were on hormone therapy and 4,000 took hormone look-alike placebos. The roughly 10,000 remaining women in that group did not take had hormones or hormone look-alike placebos.

This study was published June 26 in Menopause.

The researchers did not report any financial investments or other involvement that would influence study design or outcomes.

Reviewed by: 
Review Date: 
June 22, 2013