Dear Dr. Gott: I am a Caucasian woman, 78 years old, 5 feet 2-½ inches tall, weigh 112 pounds and am in good health. I walk every morning and ride my bike and hike whenever I can. I am not sedentary. My problem is that my bone density is not improving. I was on Fosamax for five years with no results, so my doctor changed me to Boniva two years ago. There is still no improvement.

My recent bone-density exam showed a T-score of negative 2.6 for the femoral neck. The previous one was negative 2.2. My T-score for L1-L4 is negative 1.2, and the one before was negative 1.1. My question to you is, what can I do to improve my bone density?

Dear Reader: You don't say whether you are taking calcium plus vitamin D supplements. If you are not, you should be. Take 1,500 milligrams of calcium and 400 to 600 IU of vitamin D daily. Vitamin D aids calcium absorption.

You need to know why you are continuing to lose bone mass despite treatment. It is vital this is done before serious injury occurs. You are at an increased risk of spinal-compression fractures, which can occur without trauma. You are also at risk of breaking a hip or leg due to minor falls or accidents. Given your relatively weak bones, this could mean months or even years of painful and slow healing.

Return to your primary care physician and request a referral to an endocrinologist. He or she can order additional testing to see whether there is another cause for your worsening bone density, such as thyroid disease. You may also benefit from an alternative medication, such as Calcitonin, which is derived from thyroid hormones.

Another option is Forteo. This drug is a daily injection that is reserved for severe cases that do not respond to other medications.

It should not be used for more than two years because of the increased risk of side effects. Forteo has a black-box warning because it has been shown to increase the risk of developing a type of malignant bone cancer in rats. It is unknown whether this holds true for humans, as well.

As a final note, if you are on any other medications, it is important that the physician or specialist review them to ensure they are not interacting with or counteracting the Boniva. It is also necessary to find out whether worsening bone density or calcium loss is listed as a side effect for any of them.

Doctor Gott is a retired physician and the author of the book "Dr. Gott's No Flour, No Sugar Diet," available at most chain and independent bookstores, and the recently published "Dr. Gott's No Flour, No Sugar Cookbook."

If readers would like to contact Dr. Gott, they may send their mail directly to Dr. Gott c/o United Media, 200 Madison Ave., 4th fl., New York, New York 10016, USA.