The bones of older women often get more and more brittle because they are
becoming less and less dense. Osteoporosis is the disease name for this
process, and people who suffer from it break bones more easily than normal.
For many years, women reaching menopause have been advised to
take estrogen replacement therapy (ERT) or estrogen with a progestin (called
hormone replacement therapy or HRT) to prevent this disease. But this meant
taking hormones for 20-30 years -- which also has risks, including uterine
cancer (with ERT alone), blood clots, gallstones, and possibly breast
Can I get too much vitamin D?
Too much of any good thing is a bad thing. Too much vitamin D can cause an abnormally high blood calcium level, which could result in nausea, constipation, confusion, abnormal heart rhythm, and even kidney stones.
It's nearly impossible to get too much vitamin D from sunlight or from foods (unless you take way too much cod liver oil). Nearly all vitamin D overdoses come from supplements.
The Institute of Medicine's Food and Nutrition Board's old 1997 recommendations...
There's good news, though: There may be other ways to prevent,
and even treat, bone loss.
"In the past 5 or 10 years, we have recognized that
osteoporosis is a very treatable disease," says Bruce Ettinger, MD, senior
investigator in the research division of the Kaiser Permanente Medical Care
Program in Oakland, Calif. "The old idea that you can't treat it, you can
only prevent it, is out the window. We have new medications now that markedly
reduce women's risk of fracture and we have other and perhaps even better
medications coming soon."
A June 13, 2001 Journal of the American Medical
Association (JAMA) editorial notes that the estrogen therapies
prevent postmenopausal bone loss but also that other drugs (even calcium and
vitamin D) decrease the risk of fractures independently of how dense or porous
a woman's bones are. For that reason they are approved by the FDA not just to
prevent osteoporosis but also to treat it.
One class of drugs, the bisphosphonates -- including
alendronate (Fosamax) and risedronate (Actonel) -- prevents spine, hip, and
other fractures. So-called SERM (for selective estrogen receptor modulator)
drugs -- including tamoxifen (Nolvadex) and raloxifene (Evista) -- increase
bone density and reduce spinal fractures but not hip fractures. They may
increase the risk of blood clots and hot flashes, but some reduce breast cancer
Raloxifene is the SERM that is FDA approved for osteoporosis
therapy. Calcitonin increases bone density in the spine and reduces the risk of
spinal fractures but does not seem to reduce fractures of the hip and other
bones. When injected, it may cause an allergic reaction, urinary frequency, or
nausea in some people, though these side effects were not reported when
calcitonin was taken as a nasal spray.
Statins like Zocor (simvastatin), Mevacor (lovastatin), and
Pravachol (pravastatin) may lower the risk for hip and other fractures, may
help improvej cholesterol levels, and may reduce heart attack and stroke risk,
but are not yet FDA-approved for osteoporosis therapy.
Do Benefits Exceed Risk?
Estrogen has not been shown to significantly reduce fractures
in women who are 60 years old or over, according to the authors of the
JAMA editorial. They say, "Since women in their 50s who do not have
osteoporosis have a relatively low risk of fracture, the benefit of long-term
treatment with estrogen to prevent bone loss and fractures may not exceed the