Ask Dr. H: A 'natural' osteoporosis treatment, but effective?

Question:

My gynecologist just started me on Fosteum for osteoporosis. I can't tolerate Fosamax and Actonel, so she prescribed this "natural" treatment. How well does it work compared to those others?

Answer: Fosteum is completely different from "biphosphonates" like Fosamax, Actonel and Boniva. Fosteum, a supplement available only by prescription, contains genistein (a soy-based estrogen), 200 units of Vitamin D, and 20 milligrams of zinc. It is characterized as a "medicinal food" rather than a drug. It costs around $60 per month, is taken twice a day, and is not generally covered by most managed care plans.

Fosteum's manufacturer, Primus Pharmaceuticals, does cite improvement of bone mineral density in research conducted on rats, as well as a recent study of genistein improving the bone mineral density of post-menopausal women published in the Annals of Internal Medicine.

But the unanswered question is whether that translates to a reduced risk of bone fracture. For example, fluoride supplementation will make bones dense but as brittle as a piece of chalk. Trying to reduce the risk of hip fractures and compression fractures due to weak, osteoporotic bone is more about strengthening the bone matrix than just making the bones denser. Whereas Fosamax and Actonel have clinical research showing their ability to reduce fractures, Fosteum has no such data. On the other hand, strontium ranelate is an alternative supplement that does show clinical evidence that it can reduce the risk of fractures.

Q:

On a routine blood test, my serum calcium was high, and my doctor found that my parathyroid hormone level was elevated. For now, he's just watching things. What is the implication of this?

A: With all the talk these days about calcium and osteoporosis, you might think that a disorder that causes an increased level of calcium in the blood would be a good thing. But our bodies like balance. There's a narrow range of calcium in the blood that's needed for your muscle cells (including heart muscle) to contract and function properly; for clotting; for proper nerve function; and for certain enzymes to activate normally. Too much calcium in the blood can cause confusion, constipation, kidney stones, nausea, excess urination and dehydration, muscle weakness and pain, and bone pain. To keep everything in balance, we have three regulatory hormones: parathyroid hormone, Vitamin D and calcitonin.

Parathyroid hormone (PTH) is secreted by four pea-sized glands in the neck, just behind the thyroid gland. A fall in blood calcium (or a rise in blood phosphorus) triggers PTH release. PTH increases the blood calcium level by reducing the amount of calcium our kidneys would normally excrete. Bones are a rich source of calcium, and PTH pulls calcium out of bones to maintain a proper blood calcium level. Lastly, PTH encourages more calcium from the foods we eat to be absorbed from the intestines into the bloodstream.

Vitamin D aids in the absorption of calcium from the intestines. Calcium that's not absorbed will end up in the stool as waste. If one or more parathyroid glands becomes enlarged and overactive, too much PTH is released. The calcium level in the blood will rise at the expense of bone mineral density. That can cause or accelerate osteoporosis. If the calcium level is very high, those side effects I've described may appear. Fortunately, our bodies are forgiving, and a mildly elevated calcium level won't cause any obvious symptoms.

Mild hyperparathyroidism can be watched with periodic blood calcium checks and bone density studies. If signs or symptoms do appear, surgery to remove one or more overactive parathyroid glands is the only effective treatment. There aren't any medications you can take to treat it, but watch your intake of dietary calcium.