DEAR DR. BLONZ: I've been a coffee drinker for most of my adult life, but have now read that coffee absorbs calcium -- that it can even pull calcium out of bones and lead to osteoporosis. Is that true? And if so, does adding milk or half-and-half to coffee provide calcium to counter the effect and keep it from absorbing calcium elsewhere? I have osteopenia. -- S.T., Tulsa, Oklahoma

DEAR S.T.: Osteopenia is a "warning" state where bone mass is less than normal, but not as severe as osteoporosis. Our bones and skeletal system represent a cumulative record of our general and mineral nutrition and lifestyle. This structure can also be affected by genetic predispositions and medications that affect how bones get made and maintained.

Coffee is not a significant risk factor for osteoporosis in those who eat well. Caffeine doesn't actually "absorb" or "pull" the calcium out of the digestive tract or from your bones. Still, excessive intake can have a diuretic (urine-producing) property that can bring about a minor loss of certain nutrients, including calcium and magnesium. Coffee is also an acidic beverage, and it can irritate a sensitive stomach; having food with your coffee tends to buffer this effect.

Higher intake of caffeine coupled with inadequate calcium can be a risky combination. Eating well overall -- including a sufficient intake of dietary calcium -- counters this negative. The goal is a plant-based, whole-foods diet with adequate intakes of essential vitamins and minerals, including calcium. This will have more sway than adding milk or cream to the coffee cup. (One tablespoon of milk or half-and-half will contain only about 15 to 20 milligrams of calcium.)

In an example from the literature, a study in the American Journal of Clinical Nutrition affirmed that women who drink coffee during their postmenopausal years need to pay particular attention to the calcium in their diet. They found a link between an excessive intake of caffeine and an increased rate of bone loss. In this study, "excessive caffeine" was defined as greater than 450 milligrams of caffeine per day. (Note: Caffeine in coffee can vary according to the type of bean and the way it is brewed, but consider an average to be 100 milligrams of caffeine in a 5-ounce cup of drip-brewed coffee.) The study reported that the caffeine/bone-loss effect was not present in women having diets containing at least 800 milligrams of calcium per day.

Aside from caffeine, physical activity also contributes to the health of our bones, which can be said to have a "use it or lose it" aspect. Weight-bearing exercises such as walking, jogging, gymnastics or aerobics can help strengthen the bones -- no matter what age the activities are begun. Other nutrients -- such as magnesium; vitamins A, B6 and D; phosphorous; and fluoride -- are needed for calcium absorption and healthy bones. It's also important to avoid any habitual excess of dietary protein, as this can increase mineral losses.

Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I wanted to tell you how much I enjoyed your column about grilling foods. When I was much younger, I would barbecue two or three times a week using charcoal. That went on for at least 20 years. I attributed that to my developing colon cancer when I was 54. My good friend with a similar lifestyle had the same result. So, with all of that said, you didn't mention specifically the use of charcoal -- any relevance? -- D., via email

DEAR D.: Thanks for your note, and sorry you had to experience colorectal cancer. I am hopeful that you caught it early, as that can make all the difference. We all should undergo routine screenings starting at age 45 or earlier as worked out with our health professionals. The colonoscopy, a critical screening method, is not a joyous experience, but it is trivial compared to the risks generated through avoidance.

The key concern here is the formation of carcinogenic substances when fats drop on a hot surface and get transformed. These nasties can then get carried back and deposited on the food; this can occur with grills that use gas or charcoal, and it can also happen with pan-frying and broiling. When cooking outside, care should be taken to avoid inhaling smoke, especially that from fat flare-ups. When cooking indoors, there should always be good ventilation to avoid any unintended inhalation of these nasty substances, including carbon monoxide, making it important to have a sensor nearby.

Back to your question: Possible contributors were more likely what you were making and how it was typically prepared on the grill. Also involved would be the other foods on the plate and the overall quality of your diet and lifestyle. Then, in addition to those lifestyle and environmental factors, genetic issues can also raise the risk of colorectal cancer; these can be identified by DNA health tests available to consumers.

DEAR DR. BLONZ: Is there a supplement for varicose veins and bad circulation in the legs? Mine ache, itch and feel very heavy whenever I'm standing. -- P.C., Chicago

DEAR P.C.: Rather than thinking first about supplements, your priority should be to determine what is behind the problems with your legs, including that sensation of heaviness that you feel. Check with your physician to discuss these issues. It could involve something as basic as rest or muscle tone, or some other factor for which a supplement would not be of any proven value.

When faced with an unknown, it is best to learn all you can before turning to dietary supplements. This would be especially important if there are other health issues at play and medications being used.

Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.

DEAR DR. BLONZ: I was told to take a calcium supplement, but the one I purchased says to consult your doctor if you are taking estrogen, which I am. Why is that? -- J.D., Anderson, South Carolina

DEAR J.D.: Product cautions are not to be taken lightly. But for some perspective, these warnings serve the dual purpose of alerting consumers to potential concerns while affording the product's manufacturer a measure of liability protection. There are always possibilities for unforeseen interactions. When there is a known risk, or at least a suspected one, these tend to get notations on the product label or insert.

As for the particulars of your question, calcium supplements are commonly used along with hormone replacement therapy. Other ingredients in that supplement may be responsible for the caution. Get clearance from your physician, which may involve only a simple phone call.

The bottom line is that these decisions are best made with the health professional most familiar with your particular situation.

DEAR DR. BLONZ: Is there any significant difference between the protein in red meat and that found in seafood, such as shrimp? I reduced my meat intake to once a week, but I'm concerned that I'm not getting enough protein. I do a cardio workout three days a week and also work out with weights. I am interested in adding some seafood to the menu, but wondered if that protein is as good as that found in red meat. -- S.F., Phoenix

DEAR S.F.: There are minor differences between the proteins found in red meat and seafood, and these are mainly different amounts of the various essential amino acids. Both are considered high-quality "complete" proteins, in that they both contain good amounts of all the amino acids the body needs to make its protein. To answer your question, you should consider them comparable.

Scientists score proteins by looking at the types of amino acids they contain and then comparing them with the amino acids in our body's protein. Those that compare most favorably have the highest score. Egg whites (albumin) are usually considered to be the ideal protein, followed by dairy, fish, beef and poultry. Contrast this with lower-scoring vegetable proteins, such as corn, wheat and rice, which contain some protein but lesser amounts of one or more of the essential amino acids. Be aware that the protein listing on the Nutrition Facts label does not address protein quality.

Most people have no problem getting the protein they require. In fact, in this country, we tend to eat more protein than our bodies need. We also have fewer of the plant foods that can help provide the dietary fiber and valuable phytochemicals that support our health.

The key is to have a mix of high-quality protein foods and other protein-containing foods, including grains, legumes, vegetables, nuts and seeds.

Send questions to: "On Nutrition," Ed Blonz, c/o Andrews McMeel Syndication, 1130 Walnut St., Kansas City, MO, 64106. Send email inquiries to questions@blonz.com. Due to the volume of mail, personal replies cannot be provided.