DEAR DR. BLONZ: Do I need to be concerned about taking calcium supplements if I am also taking a calcium channel blocker? If so, how do you manage osteoporosis when on this medication? -- P.T., Phoenix

DEAR P.T.: Although calcium is involved in both situations, there are important differences. Calcium channel blockers are often prescribed for hypertension (high blood pressure) because they prevent the contraction of certain smooth muscles that surround the blood vessels. For the muscle around the vessel to contract, a small amount of calcium has to pass through a channel in the membrane (outer skin) of the muscle. Calcium channel blockers are so named because they slow the movement of calcium through these channels, thereby keeping the blood vessels relaxed.

There is little connection between the calcium in your diet and the ability of a calcium channel blocker to do its job. If you have any questions about any medication you are taking, be sure to discuss the issue with the prescribing physician, or the pharmacist where you have your prescriptions filled.

DEAR DR. BLONZ: I am uncertain where else to go with this one: I have seen my regular doctor, an urgent care doctor, my dentist and an allergist and none of them have had any idea what to tell me. I am not an allergic person in general, but have had geographic tongue on and off for the last two years. My lips, tongue, gums and interior walls of my mouth swell and get numb. Then my lips peel and the numb sensation takes a week or so to go away. I’ve kept a diary of what I’ve put in my mouth the preceding six hours or so of each episode. There doesn’t seem to be too much in common. Later, I will eat some of the same foods, and have no reaction. One time I awoke at 5:30 a.m. with my tongue so swollen I couldn’t talk, and my lips were the most swollen I’ve ever seen. After swishing with a liquid antihistamine, the swelling went down.

This has been very periodic, every two weeks or so, for the last couple months. This last month, I’ve also had a very metallic taste in my mouth. Any suggestions? My next stop is an oral surgeon (a head and neck specialist). I have a feeling he’ll say the same thing. -- D.S., San Jose, California

DEAR D.S.: I am not a medical doctor -- my training is as a nutritional biochemist -- so there are limits to what I might say or can recommend. I think you have assembled a reasonable team, consulting with dentists (for teeth), physicians (for sinuses, etc) and allergists (to see if there is a provocative agent responsible).

If there are concerns about an allergy, has anyone suggested you go on an elimination diet to remove all suspected allergens? Are there new pets/animals in the house or in the neighborhood? Might there be some sort of allergenic substance already present or being brought into your environment by others? Any new dietary supplements or changes in brands of foods? New cookware? Recent dental work? New cosmetics? Have you traveled away from home during all this, and do the symptoms change when you are away?

I encourage you to give thought to all possible variables and put together a list of suspects to discuss with your health professionals. I wish you quick success on this detective hunt.

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 am hoping you will answer these questions about vitamins and minerals. Is it OK to take water- and fat-soluble vitamins at the same time? Should vitamin C be taken with foods that contain vitamin C, or is it just as effective taken alone or with water? Should calcium be taken alone or with other nutrients, such as vitamins E, C and the Bs? What's the best time of day to take vitamins? Thanks for all your help. -- G.T., Las Vegas

Dear G.T.: There is no problem taking water-soluble and fat-soluble vitamins at the same time. You can take vitamin C with or without C-containing foods. As a general rule, it is preferable to take supplementary vitamins and minerals at mealtime. When food is present, the body is more attentive to the digestive system, and its blood supply heads that way to pick up the incoming nutrients.

There are two key points to be raised here. The first is that it is more important that you get the nutrients than to be overly concerned about when during the day you get them. Second, and more on point, is the fact that it is the foods you eat that deserve the starring role. Supplements are just that: supplements. Taking supplements does not provide the equivalent of the whole-food symphony of substances produced by the plant for its growth, development and defense of the plant -- substances which then become available to benefit your body when you eat that food.

Dear Dr. Blonz: We found a couple of bottles of oil given as gifts that were tucked away in the cabinet. They have been on the shelf for approximately two years, kept away from heat and light. They are both top quality, extra virgin olive oils and have not been opened. Am I correct in thinking that they should present no problem when used? – O.S., San Jose, California

Dear O.S.: Unlike wine, oil does not improve in the bottle. An extra virgin olive oil will be at its best when first put in the bottle (or can), and it’s all downhill from there. Oils should be tightly covered and stored away from heat and light. An unopened container of a refined vegetable oil -- properly stored -- can maintain quality for about a year. Some oils, including extra virgin olive oils, claim they can last up to two years, so yours are certainly worth a check. But don’t wait! Given that they were stored properly after being opened, you have about six months. As a general rule, the more unsaturated the oil, the shorter the shelf life after being opened. Oils that have been sitting for questionable periods of time should get a sniff and taste test before being used. It is always best to buy your oil in containers that match an expected rate of use. To help you keep track, mark on the label the date of purchase, and the date the container was first opened.

Send questions to: “On Nutrition,” Ed Blonz, c/o Universal Uclick, 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: Are bacteria used to make buttermilk, somewhat in the same way as yogurt? Is this what gives it the sour taste? If so, is it as good for your intestinal flora as yogurt? -- S.E., El Cajon, California

DEAR S.E.: Starting as a byproduct of traditional butter-making, “buttermilk” was the name given to the liquid left after all butter was churned out of fresh dairy cream. Old-fashioned churning was not a sterile process; the milk sugar, also known as lactose, came in contact with bacteria in the air and in the nonpasteurized cream. The bacteria would use the lactose as fuel and metabolize it into lactic acid, which gave the fluid its distinctive, tangy taste.

At present, dairy companies must follow a general recipe to call a product buttermilk, but there are different types and no requirements that specific bacteria must be used. Acidophilus and bifidus bacteria are often used to make yogurt and other cultured milk products, but these are not necessarily used to make buttermilk. They may be added to the product for commercial appeal, however. Check the label or call the manufacturer to find the culturing bacteria present in the buttermilk you’re considering.

Beneficial bacteria used to make any cultured product can have a positive effect on the intestinal flora. Given the fact that they subsist on the unabsorbed remnants from foods we eat, our flora tend to reflect our general food choices. Incidentally, while the “butter” in its name gives the impression that buttermilk is a high-fat food, most commercial dairies use skim milk to make their buttermilks. An 8-ounce glass of a typical buttermilk contains 92 calories and only 2 grams of fat.

DEAR DR. BLONZ: How does psyllium compare with oat bran as a source of dietary fiber to be used as a supplement? -- F.S., Oakland, California

DEAR F.S.: Psyllium comes from the seed of the Plantago plant, a native to India and the Mediterranean. Used as a laxative in India for centuries, psyllium is also the main ingredient in over-the-counter laxatives in this country. On a weight basis, soluble fiber makes up 75 percent of the psyllium seed -- compare this to oat bran’s 8 percent soluble fiber.

Studies have shown that the addition of psyllium to the diet can help lower elevated blood cholesterol levels. Shortly after these studies were published, psyllium began to appear in commercial breads and cereals -- similar to what occurred when the same effect had been reported for oat bran. Unlike oats, though, psyllium has little to offer besides soluble fiber. Oat bran is a good source of protein, magnesium, iron, zinc, thiamine and phosphorus.

Care should be taken when adding supplemental fiber, as there can be side effects such as bloating, cramps, diarrhea and gas. In addition, loading up on fiber can interfere with the absorption of nutrients. This is a particular problem with supplements such as psyllium, which provides no nutrients of its own. Medications may also be affected, so touch base with your doctor before you add large quantities of fiber to your diet.

Oat bran might be a slight favorite as a supplement. An optimal approach to increasing one’s daily intake of fiber is to make a gradual shift to a plant-based diet with plenty of fruits, vegetables, legumes and whole grains. Here, the fiber is a natural component of foods that have much more to offer.

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.