DEAR DR. BLONZ: After my last health exam, I've decided to make the move to a vegetarian diet. I currently eat pretty well, having meat no more than a few times a week and fish at least once. I have heard many things concerning the lack of protein and of one kind of vitamin B in typical vegetarian diets. Do these concerns have any validity? Should I be taking a certain supplement in addition to my multivitamin? -- H.M., San Diego

DEAR H.M.: Health statistics for groups of vegetarians include lower rates of heart disease, obesity, obesity-related diabetes, colon cancer, lung cancer, breast cancer, hypertension, osteoporosis, kidney stones, gallstones and diverticular disease. Though some gains are connected to the lifestyle that's frequently adopted along with the new eating habits, these findings are certainly impressive.

Protein is rarely a problem for vegetarians eating a varied diet. However, if you are going to adopt a vegan diet -- that is, one with no animal products at all (no meat, fish, dairy or eggs) -- sources of certain essential nutrients will be harder to find. These nutrients include calcium, iron, zinc, vitamin B12 (the "B" you were referring to), vitamin D and riboflavin. You can get all of these nutrients in foods, but if you want a supplement for added insurance, these nutrients are the ones to look for. Again, if you continue to eat dairy and eggs, this is less of an issue.

In general, becoming a successful vegetarian means learning which foods are required for a complete diet. These food selections and combinations become very important -- especially with children and pregnant or lactating women. There are resources you can consult for more specific information. Nutritiondata.com provides a convenient nutrition breakdown of many foods, and it can suggest those that are rich sources of specific nutrients. Other online resources include the Berkeley Wellness Letter, tinyurl.com/le7r7l9, and the National Institute of Health MedlinePlus page: tinyurl.com/kwm6j3.

DEAR DR. BLONZ: Please don't be offended, but I am curious about where you went to school and what you studied. You are called a nutritionist, but many people use this title. Do you have a degree in nutrition? Are you a registered dietitian? -- S.S., Phoeniz

DEAR S.S.: It's never a problem to answer these questions. You are correct that many call themselves nutritionists; unfortunately, there is little regulation associated with the term's use. It is definitely "buyer beware" when seeking advice.

I did my undergraduate study at the University of Wisconsin at Madison, where I studied psychology, and my graduate degrees are from the University of California at Davis. I earned a master's degree in nutrition, working on a problem involved with food toxicology. My doctorate was also in nutrition, and I did research on the role of insulin in the development of obesity. I am not a registered dietitian. There is a brief bio online at blonz.com/bio.htm.

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: Is there a best food for fiber? I want to increase my intake and want something convenient that does not taste like cardboard. -- S.S., Concord, California

DEAR S.S.: We should aim for about 14 grams of dietary fiber for every 1,000 calories consumed, but Americans tend to eat rather low on the fiber scale. Population studies continually find that an increased consumption of dietary fiber is associated with a lower risk of diabetes, coronary artery disease and obesity. The best foods in terms of convenience and fiber content would have to be breakfast cereals: Cereal fibers are associated with the most overall importance to our health. There's no better way to start the day than with a bowl of fiber-rich cereal topped by fresh fruit. That is what I do. I also consider making time for breakfast to be a valuable adjunct to health.

If fresh fruit is unavailable for your morning bowl of cereal, consider dried fruits. They are an often-overlooked fiber resource with a great variety of rich fruit flavors, and the fact that they are dried gives them an extended shelf life. Their concentrated sugars also allow you to reduce or eliminate other sweeteners on your cereal. Dried fruits also work in your child's lunch box, or as a quick office treat, making a between-meal power snack when combined with nuts.

Next we have nuts, seeds, vegetables and grains, with legumes (beans) and whole grains being particularly low in fat and high in fiber. What about fiber supplements? There are plenty out there, and they may be appropriate when certain health issues are involved. But why even think of a supplement when you have all the fiber you need in whole grains and fresh, whole foods, which are the precise types of foods you should be eating? For more on fiber, consult the National Institutes of Health collection at tinyurl.com/2qp9l2.

DEAR DR. BLONZ: Does sunscreen prevent the absorption of vitamin D? I walk daily for about 30 minutes, but depending on the weather, I am covered with a light sweater or sunscreen. I am over 60 and take a calcium supplement with 1,000 IU of vitamin D. Am I getting any vitamin D from my daily exposure, or should I be taking additional amounts in a supplement? -- P.F., Oakland, California

DEAR P.F.: Sunscreens come in various strengths, but in general they are specifically designed to prevent ultraviolet rays from penetrating your skin. It is these rays that are necessary for the body to make its own vitamin D. You do, however, seem to have your D covered. Is there a particular reason you are considering taking more? You can discuss this with your physician. There are blood tests to determine the level of vitamin D in your body. Read more on sunscreens at tinyurl.com/kp895ep. The National Institutes of Health has a list of articles on vitamin D at tinyurl.com/mmtlu68.

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: My husband and I eat a good diet, doing our best to eat many different foods and lots of fruits and vegetables. We recently began taking a multivitamin packet of pills, along with a separate calcium, magnesium and zinc supplement, every morning with our breakfast. Soon after starting this practice, my husband started experiencing nausea an hour or two after taking the pills. I have not experienced this problem. He discontinued taking them, then tried them again a month later and experienced the same discomfort.

Is there a particular vitamin or mineral that you know of that could be doing this? His diet is not as healthful as mine, so I believe he should continue to take some sort of supplement. -- P.J., San Diego

DEAR P.J.: First, my compliments on your attempts to eat a healthful diet. While uncommon, some individuals do experience mild nausea or some other untoward gastrointestinal reaction after taking a multivitamin supplement, particularly if there are many pills involved. There may not be a particular nutrient responsible here; rather, it could be the fact that you are taking a number of pills and capsules all at the same time. When they dissolve together, they can irritate the stomach.

Check the potency to make sure that you are not getting well over the Daily Value for the nutrients. If some of the nutrients are exponentially high, your husband might try a product that provides no more than 100 percent to see if that tones down the reaction.

If one is taking a supplement, it makes sense to take it with, or after, a meal -- and the more complete the meal, the better. If breakfast in your house is typically small, you might consider taking your supplements with a meal that has a better showing of the food groups, or splitting the pills between two meals.

Whatever you decide, always remember that vitamin and mineral pills are meant to supplement a healthful diet, not replace it. This is only affecting your husband, so here are some other questions to consider: How well does he eat during the rest of the day? Does he experience indigestion at other times? Could there be a predisposing stress element involved here? How about his exercise/activity habits? All these factors can contribute to a vulnerability to digestive issues. The National Institutes of Health has a good discussion of indigestion at tinyurl.com/3do3ld. And here is a link to a page offering tips for buying multivitamins: tinyurl.com/pwngld8.

DEAR DR. BLONZ: Thank you so much for your clear, scientifically based, helpful comments about smoking cessation. These days, there is so often a promulgation of nonsense "tips" like colon cleansing. -- R. Oehm, cardiologist

DEAR DR. OEHM: Thanks for your note. As a physician, you understand that the cells that make up the lining of our intestines are constantly being replaced. As reported in the March 2009 Annual Review of Physiology, there is a change in this layer of cells every four to five days! The idea that toxins are caked onto these cells, and that they hang around for months or years to wreak havoc with our health, is baseless. There remains, however, that subculture that opts for the archaic flushing procedure with the promise that it can provide just about any beneficial health effects that one might seek.

The whole foods and fiber we eat determine how well our digestive and elimination systems work, and they should be viewed as an essential part of our daily diet. The message here is that it is our diet and lifestyle, not colon cleanses, that contribute to our overall state of health.

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.