DEAR DR. DONOHUE: I am a man, age 68, in reasonably good health. I take a multivitamin/mineral tablet daily. Last autumn, I had a bone scan that showed moderate to severe osteopenia. My physician put me on Fosamax. I recently read an article about vitamin K and its role in bone health. The article said that Coumadin increases the risk of osteoporosis by blocking the action of vitamin K. How does it do so? Does that apply to aspirin too? – J.V.

ANSWER: Coumadin prevents clots from forming by interfering with the production of “clotting factors ” – blood proteins that combine with blood platelets to form a clot when a blood vessel is broken. Vitamin K is essential to the formation of clotting factors. If a person on Coumadin takes large doses of vitamin K, the vitamin can overpower Coumadin’s slowing down of clotting factor production, and the blood once again forms clots easily. That’s something that people on blood thinners don’t want to happen.

Vitamin K has another action. It retards bone breakdown and enhances bone building, a great benefit in fighting osteoporosis. This is a little-appreciated side effect of vitamin K.

You have osteopenia. It’s not quite osteoporosis, but it’s a giant step on the way to osteoporosis.

What’s a person on Coumadin to do if that person needs vitamin K? He or she can increase the dose of Coumadin so the person gets the benefit of blood thinning and the benefit of vitamin K for bone strength. This has to be done with a doctor’s instructions.

Aspirin doesn’t fit into the vitamin K story. It doesn’t have any effect on the body’s production of clotting factors. It works against blood platelets – an entirely different aspect of the clotting story.

DEAR DR. DONOHUE: Will you comment on taking the injectable hormone Forteo for osteoporosis? It must be refrigerated and injected daily. What if a dose is missed? Travel could be complicated with such an inconvenience.

My doctor recommends Forteo. I am resisting its inconvenience. – M.M.

ANSWER: Forteo is a synthetic version of parathyroid hormone, the hormone made by the four small glands that lie behind the thyroid gland in the neck. Forteo, like parathyroid hormone, helps form new bone, increase the level of calcium in bone and strengthen bone. Forteo is wonderful drug.

The inconvenience of Forteo isn’t as great as you might think. Using the injector system is simple. Diabetics have no trouble giving themselves insulin. You won’t have any trouble giving yourself Forteo.

If a person misses the usual time for taking Forteo, he or she can take it anytime that day. However, a person should not take more than one injection in one day. If a dose is completely forgotten, don’t make it up the next day.

Keeping the medicine cool is somewhat of a problem, but it doesn’t present a great obstacle to travel. Many boats, trains and other conveyances can store it for you. Hotels either have a room refrigerator or can assist you in keeping it stored properly. Polar Bear Coolers sells an 8-inch-by-3-inch portable cooler. The company can be reached at 888-438-7924. The Eli Lilly Company, maker of Forteo, will supply you with a traveling kit that keeps the medicine cool. You can reach the company at: 866-436-7836. Or you can get a wide-mouth thermos and use it as a storage receptacle.

DEAR DR. DONOHUE: I am 77. I have had two husbands. Both died. My health is good, and I walk a lot. I drink three or four glasses of red wine a day. Does that make me an alcoholic? My kids think I drink too much. – M.C.

ANSWER: You’re drinking more than the recommended amount for a woman. That amount is one drink a day. A drink is 5 ounces of wine, 12 ounces of beer or 1.5 ounces of 80-proof liquor. A man is allowed two drinks a day.

This isn’t a sexist thing. A man’s larger body mass permits him to handle more alcohol than a woman can.

Alcoholism is defined by the volume of alcohol drunk and the degree of life impairment caused by drinking. Your volume qualifies as alcoholism, but life impairment is something you have to judge for yourself.

DEAR DR. DONOHUE: I am a person between 65 and 80. I’ve noticed that my fingernails have taken on a condition that I’ve never heard talked about. From the cuticle to the tip of each nail, there are raised surface ridges. The nails no longer have a smooth surface. I am puzzled as to what could have caused this to happen. What did? – M.G.

ANSWER: I don’t know the cause, and I don’t know anyone who does. I do know that those ridges are very common and very normal. They most often appear at older ages, like gray hair. They’re not a result of vitamin deficiency or an infection, nor are they a sign of anything dire.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com