Another biphosphonate, alendronate, is being studied, and the quality of bone formed appears normal. At the three year mark, double blind studies show a decreased fracture rate, an increased bone mass and normal bone quality. Other biphosphonate drugs are also being developed.

Estrogen and calcitrol have a similar mechanism as the biphosphonates in that they block the resorption of bone. Calcitrol is an active form of vitamin-D called vitamin-D3. Some studies showed that calcitrol does increase calcium absorption, improves calcium balance and reduces bone loss. Other studies showed conflicting results. Problems with vitamin-D3 include the high cost and the risk of elevated blood calcium levels. An editorial in the New England Journal of Medicine (Feb 6/92) says that this form of vitamin-D is still an experimental treatment that warrants close follow-up with monitoring of blood and urine calcium levels and kidney function.

How the effect of estrogen and calcitrol on the bone compares to the biphosphonates has yet to be studied.

Calcitonin was discovered in the early 1960's in Canada by Dr. D. H. Copps. Calcitonin is a hormone secreted by the thyroid gland of mammals, birds and fish. It acts to inhibit bone reabsorption. It must be given by intramuscular injection or nasal spray. Calcitonin reduces early bone loss during menopause and is also very useful to reduce pain and to increase mobility after fractures have occurred.

Currently the only agent that simulates bone formation of the spinal bones is sodium fluoride. However, there is controversy about whether the fluoride-treated bone has normal strength.

New Research On Progesterone Alone Preventing Bone Loss

As mentioned before, bone loss in menopause occurs most rapidly in the first five years after menopause and then slows down. New York physician Dr. Carolyn Dean calls this period "bone-pause" and says that during that time the body temporarily rejects calcium and thus bone loss increases. However, after this initial period of time, she believes that bone loss seems to stabilize, especially with an optimal diet, supplements and exercise program.

Recent evidence from Dr. Prior and Dr. John Lee indicate that it may be the progesterone, and not the estrogen, that is the most positive hormone for the bone. In many recent studies on the effect of estrogen on bone loss, progesterone was given as well. So it is not possible to know which hormone was responsible for the improvement in the bone or how the two hormones interact together.

Dr. John Lee is an internationally recognized authority on fluoride and osteoporosis, and a clinical instructor at the University of California Medical School, Department of Family Medicine. For over ten years, he has been studying the effects of natural progesterone on bone loss. "Natural progesterone," explains Dr. Lee, "...declines to a lower rate than estrogen does with menopause, and it is the key hormone in causing these bones to regain their normal activity for strength and long life."

Dr. Prior made a detailed study of 66 women (New England Journal of Medicine, Nov 1/90). Twenty nine percent of these women were not ovulating even though they were having regular periods. These same women had low serum progesterone levels and were losing two percent of bone annually. If this holds true for the general population, says Dr. Prior, then many women are losing bone before menopause. Dr. Prior found she could reverse the bone loss by giving 10mg of Provera (a synthetic progesterone) daily for ten days a month.

Although one study showed there were no significant side effects if Provera or synthetic progesterone was given with continuous use of the estrogen skin patch, many users of Provera report troublesome side effects. On the other hand, natural progesterone, which is identical to the body's own progesterone, has few side effects except drowsiness. However, it is difficult to take by mouth because it is destroyed by stomach acid. It must be made into special preparations to be absorbed (oral micronized, vaginal and rectal suppositories or topical creams).

In a report published in the Lancet (Nov 24/90) of 100 women applying a natural progesterone cream to their skin, Dr Lee documented bone scan increases in bone density over three years ranging as high as 22 percent. The amount of bone increase was proportional to the bone loss before treatment. This means that patients with the lowest bone density before treatment would gain the greatest amount of bone during treatment.

Dr. Lee has also published an excellent article on his work entitled, OSTEOPOROSIS REVERSAL, THE ROLE OF PROGESTERONE (Intern Clin Nutr Rev pgs-384-391/90), as well as a more comprehensive book on natural progesterone entitled, NATURAL PROGESTERONE, THE MULTIPLE ROLES OF A REMARKABLE HORMONE.