DEAR DR. BLONZ: A recent visit with my doctor revealed that my thyroid is low, and she recommends I begin taking a synthetic thyroid hormone. I’m considering it, but I confess that I prefer natural methods, because my body doesn’t always respond well to medication. Can you suggest ways, other than a synthetic supplement, to raise my thyroid level? Would it be wise to take an iodine supplement? -- S.T., Tulsa, Oklahoma

DEAR S.T.: Thyroid hormones regulate the metabolism in the cells of the body. To release its hormones, the thyroid gland, which sits just below the larynx (voice box) in the throat, requires the mineral iodine and the stimulating presence of another hormone: the appropriately named thyroid-stimulating hormone (TSH). Hypothyroidism is the condition of insufficient thyroid hormone. This can be due to problems with the gland itself, or due to an insufficient amount of TSH. There are a number of medical conditions that can play a role in hypothyroidism, so your doctor should fill in the details of what’s going on in your particular case. (Read more about this at tinyurl.com/yd26athu.)

You mention iodine; a deficiency of this essential mineral can indeed hamper the ability of the thyroid gland to produce its hormone. In such cases, the thyroid gland often enlarges, and the condition referred to as a “goiter” results, with a characteristic swelling about the front of the neck. Most people, however, get more dietary iodine than they need, so it is unlikely that an iodine deficiency is the problem.

It wasn’t always that way. Iodine is plentiful in the ocean, but there was a time when it was not well-distributed inland. Foods containing iodine used to be limited to seafood, crops grown in coastal areas, and dairy or meat products from animals that had grazed on iodine-rich feed. During that period, iodine-deficiency goiters used to be more common. With the advent of iodized salt, perhaps our first “functional food,” this condition virtually disappeared. The typical iodine intake is now well above required levels.

Be aware that if you are not iodine deficient, taking additional iodine will not cause your thyroid to produce more, and excessive intakes can be harmful.

There are compounds called goitrogens that can interfere with the use of iodine by the thyroid gland. These compounds are found in foods such as cabbage, Brussels sprouts, kale, cauliflower, broccoli, kohlrabi and turnips. Goitrogens, however, tend to be inactivated by cooking, so unless you are eating lots of these vegetables raw, and on a daily basis, it’s doubtful that they would be involved.

Whatever the cause, if you have hypothyroidism, it is important that your condition is treated. The symptoms of inadequate production of thyroid hormone include sluggishness, intolerance of cold temperatures, depression, poor muscle tone, and weight gain. There is also an increased risk for heart disease. The use of Synthroid (a synthetic thyroid hormone) may be a reasonable option, but make sure you discuss all your concerns with your physician.

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 try hard to limit my daily salt intake, but some foods need a little extra flavor. I tend to use seasonings such as onion powder and garlic powder in place of onion salt and garlic salt, but what exactly is the difference between the powder and the salt? Is there any salt in the “powders,” and am I doing any good at all by making the substitution? Any other suggestions? -- I.D., Walnut Creek, California

DEAR I.D.: As a general rule, if a seasoning has “salt” in the name, expect there to be salt (sodium chloride) in the product. But whatever the name, the way to know for sure is to consult the ingredients statement and check the level of sodium on the Nutrition Facts label.

Individuals concerned about salt/sodium need to shift away from a mindset where a desire to add flavor automatically translates to “more salt.” As you indicate, seasonings such as garlic or onion powders (or granules) can be helpful. They contain no salt, and in addition to their flavors, they will contain the naturally occurring phytochemicals found in these healthful foods.

It is difficult to make generalizations about what types of seasonings work with what foods or methods of preparation. It would be nice if we each had an experienced chef nearby to provide needed advice! Absent this, we can consult a cookbook, magazine or online recipe resource. Every week, the food sections of local newspapers present new ways of preparing foods. It helps to acquaint yourself with the variety of flavors available through herbs and spices, and how they work. There are many resources out there, but one I continue to recommend is “The Spice Lover’s Guide to Herbs and Spices” by Tony Hill.

DEAR DR. BLONZ: What is white distilled vinegar made from, and how is it made? Is it healthy or harmful? -- F.T., Hayward, California

DEAR F.T.: Vinegar has been used as a flavor enhancer, preservative and folk remedy since 5000 B.C. Vinegar comes from fermented carbohydrate, and there are many varieties, their particular flavors depending on the type of carbohydrate used. White distilled vinegar comes from the distillation of grains -- mostly corn, but also rye and barley.

The acid in vinegar is acetic acid, and it is usually present in solution at about four parts in 100 (4 percent acidity). White distilled vinegar’s main failing is that it has a strong acidic taste. It can be used in foods, but it is perhaps best suited for pickling.

Vinegar does not provide any needed nutrients. It is not unsafe or harmful if used appropriately. For more on vinegar’s possible health attributes, see tinyurl.com/yaxcedxq.

DEAR DR. BLONZ: Quick question: I was wondering about the nutritional content of frozen vegetables. I eat them daily, heated up in a microwave for a minute or two. Are these a good source of vitamins, or am I kidding myself? -- S.J., Dover, New Jersey

DEAR S.J.: Assuming it is stored properly, the nutrition of a frozen food is up there with the fresh version’s.

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: At a recent lecture, a doctor of natural medicine touched on the topic of milk homogenization, saying that it could be a major cause of heart disease and should be avoided. As it was explained, this theory was put forth by the chief of cardiology at a hospital. Proponents of this theory point to the fact that heart disease rates are much lower in countries, such as France, that don’t homogenize most of their milk, and higher in countries, such as Finland, that do. Do you know if any studies have been done, or are in progress, to substantiate the damaging effects of homogenization?

Also, are dairy products such as yogurt and cheese subject to homogenization? -- J.L., Casa Grande, Arizona

DEAR J.L.: Hearing something at a lecture does not make it so. There is little scientific support for these charges.

Milk is about 3.7 percent fat by weight as it comes out of the cow. The fat exists in globules of various sizes. If allowed to sit, these fat globules would rise to the top because fat is less dense than water. Homogenization is a physical process that changes the size of the milk-fat globules into a smaller, more uniform size. This is accomplished by forcing the milk through a small opening under pressure. After that, the milk fat remains evenly distributed throughout the milk, and the globules do not rise to the top.

One exception to this would be if the milk were frozen: When that happens, the water forms into ice crystals that separate from the fat. Upon defrosting, the fat globules will once again rise to the top as they did before the milk was homogenized.

Most commercial milk products, including yogurt and cheese, are made from homogenized milk.

DEAR DR. BLONZ: I am hoping you can explain something for me. The front label of a product I use says “sweetened only with malted barley,” but the nutrition label says the product has “13 grams of sugars.” Can both be correct? This is important for me to know, as I am a diabetic. I like the product, and I would like to keep using it. -- F.D., Berkeley, California

DEAR F.D.: Malted barley is produced by allowing the barley grain to sprout. This causes the grain to produce higher levels of a starch-digesting enzyme that breaks the grain down to simpler sugars. The 13 grams of “sugar” are probably maltose, a double-sugar that breaks into two molecules of glucose upon digestion. As a diabetic, you should treat maltose as you would any sugar.

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.