DEAR DR. BLONZ: My husband has high blood pressure and is watching his salt intake. He thinks he is being careful by not adding salt to his foods, but to me, that is only the most obvious part; it is all the hidden sodium I am concerned about. Processed foods and condensed soups have a lot of sodium, but since it is not in a form that means anything to us, it doesn't really hit home how much it is. If I could picture the sodium in a frozen dinner entree, for instance, in spoonfuls rather than milligrams, that might help. How many milligrams of sodium are there in a teaspoon of salt? -- K.M., Sedona, Ariz.

DEAR K.M.: With the exception of sugar, we add more salt to our food than any other condiment. There are 2,325 milligrams of sodium in one teaspoon (6 grams) of salt. The Daily Value -- that single set of values developed for use on food labels -- recommends an upper limit for sodium of 2,400 milligrams per day. Our health can be maintained with as little as one-tenth of that teaspoon of salt per day. As a country, we are consuming much more sodium than is necessary: The average sodium intake in the United States is between 4,000 and 5,000 milligrams per day.

About 10 percent of the salt we eat is naturally present in food, and 15 percent is added during cooking and at the table. The remainder, 75 percent of the salt in our diet, comes from processed foods.

Salt is added to processed foods for a number of reasons. Depending on the level used, it can slow the growth of certain microorganisms. Before refrigeration, salting was the only practical way to keep meat and fish from spoiling. Salt can also play a role in food texture: Processed meats such as bologna, hot dogs and lunch meats contain higher levels of salt because it helps maintain the consistency of the product. Then, of course, there is salt's role as a flavor enhancer.

The concern about excess salt is its association with hypertension, or high blood pressure, which currently affects about 50 million Americans. Hypertension is defined as blood pressure readings above 140/90. The first number (140, in this case) is the measure of the pressure in the arteries when the heart contracts and the second number (90) is the pressure in the arteries as the heart relaxes between beats.

Hypertension is called "the silent killer" because there are no warning signs until problems such as heart disease, stroke or kidney disease have already developed. There is more information at tinyurl.com/d7o7mmb. The only reliable way to find out whether you have hypertension is to have regular blood pressure checks.

Impressive data coming out of DASH (Dietary Approaches to Stop Hypertension) studies show how blood pressure can be lowered by decreasing sodium intake along with a low total- and saturated-fat diet rich in fruits, vegetables and low-fat dairy.

The bottom line? Read your labels, avoid foods overloaded with sodium and try to focus on the natural flavor of food -- not that which comes from the salt shaker.

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: I would like to know if taking Nuvoryn, which I've heard a lot about, really does make you lose weight. I am healthy and I do not suffer from health issues. I have read about so many tablets on the market, and would like to know which is the healthiest and safest one to use -- and most importantly, if they work. -- F., via email

DEAR F.: According to available information, this product contains a proprietary blend of green tea, guarana (caffeine), acai, resveratrol, hoodia, Siberian ginseng, Damiana, pomegranate and yerba mate. I was unable to find any evidence in the scientific literature that taking this product's ingredients as directed had ever been shown to cause significant weight loss in people.

On what basis is it being promoted? It is very important that you are not swayed by testimonials featured on a site that sells the product. Proof from an independent source is needed. Sorry for the negative response, but it is important that weight-loss efforts not get vested in a product where there is no objective evidence that it is likely to help. The resulting disappointment can turn us off from sincere efforts to effect change, and that is bad news.

My advice is to start by sitting back and acknowledging that it took a period of time for that weight to come on board, and it's likely that it will take time for it to "get lost." Getting to a point where you slowly drop a pound or two a month would be fantastic. Adding calorie-burning activities to diet changes is what makes this happen. Be patient. Nothing from a dietary supplement bottle should be thought of as more important than the changes you make in what you eat and in your level of physical activity. As always, if you have been sedentary for a long time, are on medications, or you have a chronic health condition, run your plans by your health professional before you start.

DEAR DR. BLONZ: I read a recent column about hydrogen peroxide with interest. Most teeth whiteners have hydrogen peroxide as a primary ingredient. Although these are not swallowed, do they pose a risk to gum tissue? -- M.D., via email

DEAR M.D.: The levels of hydrogen peroxide in these products, and their instructions for use, should be designed to prevent damage to gum tissue. There are approval processes for over-the-counter products, and companies are required to notify the FDA about their products and intended uses prior to sale. But you cannot assume that every product or device is safe and effective.

Please exercise due diligence prior to use by, for instance, doing research online at independent professional sites (not the sites selling the products). You can also check with the American Dental Association site at mouthhealthy.org to see what they have to say. The professionals in this area are your dentist and dental hygienist; I would put great stock in their recommendations as they have familiarity with your mouth and any particular issues you might be facing. They should also be up on the latest products.

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: Does the freezing of milk harm any of its nutrients? How about lactose-free milk? Military families have been freezing milk for years, but I have never found out if it is a good thing to do. -- M.M., Janesville, Wis.

DEAR M.M.: Freezing is a safe and acceptable way to store milk and the changes in nutritional value would be negligible. This would be the case for any type of milk, including a lactose-free product. In some cases, there will be a few minor changes in the way the milk appears and tastes. Freezing can cause a breakdown of homogenization, the process that distributes the milk fat evenly. This will not be an issue with nonfat milks, but there can be an occasional drop of fat seen floating around in low-fat, reduced-fat or whole milk. The best way to remedy this is to shake the container before drinking.

Depending on the speed at which the milk is frozen, there can be slight changes in taste and color. In addition, a small amount of sediment may develop. These changes are negligible and do not reflect any change in the wholesomeness of the milk. A good rule of thumb is the faster the freeze, the smaller the damage. You can foster a quicker freeze by placing the container next to the freezer wall or on a metal shelf.

Remember, also, that because milk is a rich source of nutrients, it provides an ideal food for bacteria and other microorganisms. Pasteurization helps destroy most of the bacteria that are present at bottling, but not all. Freezing does not destroy microorganisms, it just suspends or slows their growth. The quality of the defrosted milk will be no better than that of the milk at the time it was frozen. It is always best to put the milk in well-sealed containers.

DEAR DR. BLONZ: I am a 70-year-old woman and have been told by my doctor that my body does not absorb vitamin B-12 because I do not have the intrinsic factor needed for absorption. He said that I need to get a monthly B-12 shot. Recently, I have come across an advertisement for a sublingual B-12 supplement. How effective is taking B-12 this way, and could I be able to discontinue my monthly shots? -- G.S., Nashville, Tenn.

DEAR G.S.: There is some research evidence that sublingual (under the tongue) drops of vitamin B-12 can be effective. Nasal sprays can also work. These are not as efficient routes as injections, so it may not be as effective in every case of vitamin B-12 deficiency. Another factor to consider is that about one percent of vitamin B-12 is absorbed in individuals, like you, who do not have the intrinsic factor. This means that taking a higher oral dose might satisfy your requirement. I would encourage you to discuss all this with your health professional and follow what would be best for your particular situation. There are two papers you might mention that cover this issue: one in the Aug. 28, 1999 issue of the journal Lancet, and the other in the December 2003 issue of the British Journal of Clinical Pharmacology.

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.