DEAR DR. BLONZ: I enjoy the speed and convenience of cooking vegetables in the microwave, but became quite concerned when I read that this method might be destroying nutrients. Should I steam my vegetables instead of microwaving them? -- Q.T., Austin, Texas

DEAR Q.T.: It is reasonable to want the most from what we eat. Eating should be one of life’s great pleasures, and it makes no sense to sacrifice that enjoyment on the altar of requiring every last milligram of every nutrient.

Cooking can reduce the levels of certain nutrients, but it makes others more available for absorption. The answer to your question comes down to a matter of preference, and of using the technique with which you feel most comfortable.

The difference in nutrient composition after cooking is based primarily on the temperature and time of exposure. Microwaving is among the least destructive methods. Another issue is whether the food is submerged and cooked in water that then gets discarded; in this case, the cooking water can contain some of the water-soluble nutrients.

Steaming and microwaving are similar in both respects, so run with whichever you prefer. The most important factor is that you are eating and enjoying the bounty of fresh summer vegetables. Kudos on good eating habits, and their contribution to your health.

DEAR DR. BLONZ: Salt is a straightforward compound, so why does table salt need to contain additives? I know that they make salt iodized by adding a compound that contains iodine, but why are they adding other compounds such as calcium silicate and silicon dioxide? I have absolutely no problem with blood pressure, and use salt on occasion. Would I be better off using a natural salt or a sea salt where these compounds are not used? -- T.S., Sun City, Arizona

DEAR T.S.: Crystals of table salt are composed of sodium chloride, which can stick together when exposed to moisture in the room’s air. Salt that clumps together can have a hard time making it out of the shaker. One method to avoid this is to add dried rice or crackers to the shaker to absorb any moisture and keep things flowing. Another approach is to add very small amounts of compounds such as calcium silicate or silicon dioxide. (Silicon dioxide is the same compound in sand and quartz crystals.) These anti-caking substances are harmless at the levels used.

It is totally up to you: You can opt for a free-flowing product or one that needs more of a shake to be dispensed.

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: Sometime earlier in the year, I began adding a tablespoon of flaxseed to my morning granola. After about one week, I began to experience symptoms of vertigo. One day it was so bad that I could not even get out of bed in the morning. I have never experienced symptoms of vertigo before, so I thought it might be the flaxseed that was responsible. I stopped taking it, and the symptoms disappeared. Have you ever heard of such a case? -- F.D., Hayward, California

DEAR F.D.: Seeds are often sources of substances associated with food allergies, but reactions to flax are not common. Such an occurrence, however, is not out of the realm of possibility. The experience you relate certainly does cast suspicion in that direction. But your query highlights a situation we all must acknowledge: namely, that untoward reactions from foods do not always present with a clear connection between the cause and the effect.

When we experience something unexpected after eating, it is reasonable to consider the last thing consumed as a likely suspect, especially if it was something new. If it seems to recur whenever it’s eaten, we start to think we are on solid footing. What happens, however, if there is little basis for the connection, and our health professionals are unable to offer guidance?

If we are confident in our decision, we might act on our assumptions and cross the suspected offender off our “to eat” list. We might, however, be persuaded by the guidance of health professionals and begin to look elsewhere to explain the reaction. Or, we might simply chalk up the reaction as one of the many unexplained events experienced in life.

The bottom line here is that medical science is not always able to tell who will react to what. And while it may be a single substance you are reacting to, it may also be the dose that determines the reaction. For some, any amount of intake can cause problems, while others will only react if they take in more than their “threshold” of sensitivity. To further complicate the issue, there may be other foods or medications that change that threshold. Have a set amount of that certain food alone, no problem -- but have that same amount along with another food, or in a particular situation, and you experience the reaction.

There can be quite a detective game afoot, which is why it makes sense to keep a log of all foods consumed to help identify any patterns.

Research studies tend to say what is likely to happen to the “average” individual under a controlled set of circumstances. Such information can provide valuable insight, but regardless of what a study might tell you, we are all unique. Arm yourself with the required knowledge, then collect information about the reaction and the circumstances associated with its occurrence. Then, consult with a trusted health professional to exercise due diligence to chart the path forward.

Science is only as good as the latest study, so as new information and experiences become available, be prepared to reexamine your choices and make the appropriate changes. While it is essential to control items that make us ill, it is best to avoid dubious assumptions that continually shrink the circle of foods we can enjoy.

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 have pernicious anemia, for which I receive B12 injections. Why is it that intrinsic factor cannot be synthesized and introduced into the body by injection or pills? It seems as though that would be better. -- T.D., Anderson, South Carolina

DEAR T.D.: As you know, but other readers may not, two separate components are needed for vitamin B12 to be absorbed. The first is the vitamin itself, and the second is a protein manufactured by the body that is called the “intrinsic factor.” That factor links with vitamin B12 and provides the escort that carries it through the absorptive surface of the intestines. Without its intrinsic factor, little, if any, vitamin B12 would ever get into your system.

Pernicious anemia, which only occurs in about 2% of individuals, is when the stomach produces an insufficient amount of that intrinsic factor protein. When this is the case, dietary sources of vitamin B12 do not get absorbed. We cannot get the same effect from taking intrinsic factor as a dietary supplement, as it will get broken down like other nutritional proteins.

To date, the most workable treatment for pernicious anemia is the periodic injection of the preformed vitamin B12. The strategy should be worked out with your health professional, who can help identify factors or medications that may be involved. I encourage you to discuss whether your situation is one where alternatives might be available, such as elevated oral doses of vitamin B12, or ones administered as a sublingual tablet, nasal gel or spray.

Check out the additional discussion at the National Institutes of Health at b.link/pernicious.

DEAR DR. BLONZ: A lady in my office says that she was told the calcium in milk is the wrong kind for our bodies, and is not easily absorbed. Since she is pregnant, I’d like to be sure this is correct, so she’s not ignoring something important. Is there any truth to this? -- M.M., Phoenix, Arizona

DEAR M.M.: No. The idea that the calcium in milk is the “wrong kind” is without merit.

There are many types and dietary sources of calcium. Dairy products represent an excellent and convenient source. One advantage is that the body absorbs a higher percentage of dairy calcium than calcium carbonate, which is a common form of calcium found in dietary supplements.

A key consideration here is that while calcium is essential -- especially for a mother and her developing child -- dairy products are not.

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.