DEAR DR. BLONZ: I have been a vegetarian for about 10 years. Lately I have been having problems with muscle discomfort in my shoulder, and some people have been telling me that it might not be healing correctly because I do not eat red meat. I don’t buy this at all, but was wondering: Is there anything I should supplement my diet with, since I no longer eat red meat? -- K., San Diego

DEAR K.: A plant-based, whole-foods diet is the way to go, and good nutrition is good nutrition, whether or not there’s ever meat on the plate. You did not mention whether you consume other animal products, but if you eat vegetarian, there are some nutrients you should be mindful of. These include vitamin B12, calcium, iron, zinc and vitamin D.

In most cases, getting adequate protein doesn’t represent any problem for vegetarians. Amino acids are the building blocks of protein, and of the 22 different amino acids, our body can manufacture all but nine. These nine, referred to as the essential amino acids (EAAs), need to be supplied by our diet. Most foods contain some amino acids. Animal proteins, such as meat, poultry, fish, eggs and dairy are considered “complete” proteins because they contain all the EAAs.

Except for soybeans, vegetable proteins such as grains and legumes are incomplete proteins because they lack one or more of the EAAs. Vegetarians easily meet their daily protein requirement by combining different foods so that sufficient amounts of all the EAAs are consumed over the course of the day.

Vitamin B12 is needed for red blood cells and nerve tissue, and it is only found in bacteria and animal foods. Vegetarians can use specially fermented soy products, such as tempeh or miso, as a dietary source for B12, or rely on foods fortified with it.

If you consume dairy products, there shouldn’t be a problem getting enough calcium. If not, you will have to rely on calcium-rich foods such as broccoli, dark green leafy vegetables (such as kale and turnip greens), calcium-set tofu, almonds, figs and some legumes. There is also the growing variety of calcium-fortified non-dairy milks, and fortified orange juice.

Red meat is an excellent source of iron, but it is also found in dark green leafy vegetables, legumes, raisins and prunes. Iron absorption is facilitated by acidic foods, such as citrus juices. Zinc, which can also be in short supply for vegetarians, can be found in nuts, seeds, whole grains and legumes.

Vitamin D, needed for calcium absorption and bone formation, is another nutrient that’s not widely available in vegetarian cuisine. Besides food sources such as fish and fortified milk products, the body produces this nutrient upon exposure to direct sunlight. An alternative is to rely on a supplement.

Back to your question about that muscle problem that is not healing: Your physician or health professional may have done routine blood work, and this can help verify if there are indications of a nutritional deficiency. You might also consider getting a referral to a physical therapist, who might help with specific strategies and exercises to help strengthen the affected muscle and get that discomfort into the history books.

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: Our reading group was discussing milk, and one of the long-standing members argued that milk, especially homogenized milk, is a bad and even dangerous food for seniors. How can this be? I remember it being called “nature’s most perfect food.” I was hoping you could explain if things have changed, and whether milk is a food to avoid. -- L.I., San Jose, California

DEAR L.I.: One valid reason to avoid milk and milk products would be if you had been tested and found to be allergic to milk protein. Another motivation might be lactose intolerance: a dislike of side effects experienced due to an inability to digest the lactose carbohydrate that milk typically contains. Common lactose intolerance produces intestinal gas or other digestive upset. Some don’t experience symptoms unless milk is consumed on an empty stomach, or if more than a certain volume is involved. Many with lactose intolerance have no problems with yogurt and cheese.

Concerns about homogenization often come from a paper that suggested that an enzyme naturally present in milk (xanthine oxidase) might contribute to the risk of inflammation and several chronic ailments. It was nothing more than a hypothesis, but it was adopted by what became an “anti-milk” crowd. The human body produces its own xanthine oxidase, and it is associated with inflammation, but there is no solid evidence that consuming it in milk has negative health effects. It’s helpful to remember that proteins -- and enzymes are proteins -- are disassembled during digestion, before absorption.

There is now a growing variety of nondairy milk, and new twists on the dairy version. Lactose-free milk products represent an option for those with the intolerance issue, and some milk products are now offered that contain a slightly different protein. The protein in milk is beta casein, and cows can produce two versions: A1 and A2. Most cows’ milk contains a mix, but there are now milk and dairy products from cows that only make A2. The argument is that negative health effects and discomfort from milk might be related to the A1 protein specifically, not lactose. This is an emerging theory, and the evidence is far from solid. Those who have a milk protein allergy, of course, should avoid either kind.

Assuming you are not eating vegan, and absent an allergy or intolerance to one or more of its components, there are few health reasons to avoid milk. I wouldn’t call milk “nature’s most perfect food,” and it’s certainly not “essential,” but it does have much to offer nutritionally. There are many spreading twists on the “milk is bad” message, but the negative allegations, thus far, have failed to stand up to the light of science. For more on milk, check out b.link/milk27.

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: A recent ad for pour-over coffeepots with reusable metal filters stated that the filters allow more of the “tasty and healthful oils” to come through, as compared to paper filters. Years ago, I read that paper filters reduced the amount of unhealthy cortisol oil in coffee. I’d appreciate your view on the use of paper filters versus metal. -- D.M., via email

DEAR D.M.: While you are correct that paper filters can trap oily substances drawn out of the ground coffee by hot water, there is no cortisol in those beans. What you may be referring to is “cafestol” or “kahweol,” two substances in coffee beans that can indeed be trapped by a paper filter.

Coffee consumption is associated with beneficial effects, but cafestol and kahweol can affect a cholesterol-regulating receptor, which gives coffee a bit of a split personality. (Ironically, those two compounds may also be associated with some of coffee’s benefits.) A paper in the September 2019 issue of Nutrients (see b.link/coffee24) suggests that intakes of up to two cups of coffee a day do not appear to cause problems.

The use of a paper filter reduces the risk from these substances. The single-serving method is also covered, as pods often include, or can be used with, a paper filter. Those with a blood cholesterol issue who drink lots of unfiltered coffee may want to reconsider their brewing method.

DEAR DR. BLONZ: What are the health risks in having a diet rich in potassium? All items on a list of high-potassium foods are ones that are necessary for maintaining healthy muscle and nerve function. So why would a low-potassium diet ever be recommended? -- L.K., Oakland, California

DEAR L.K.: Potassium is a key mineral that helps regulate water balance inside the cells. (Sodium, by contrast, regulates water balance outside the cells. I bring this up because a high salt intake causes a greater fluid volume in the bloodstream, and this contributes to the increased risk of high blood pressure.) Potassium is also involved in the transmission of nerve signals (it keeps the heart beating), muscle tone and in the body’s acid-base balance. Adults should consume about 4,700 mg of potassium per day from the foods they eat.

A healthful diet would be naturally full of potassium-rich foods, as potassium tends to be found in fruits, vegetables and other whole foods. It is difficult to overdo it on healthful foods. The best food sources for potassium include bananas, prunes, potatoes, beet greens, chard, tomatoes, citrus fruits and avocados.

But it is never good to have too much of anything, and potassium is no exception. There are certain health conditions and medications that can upset the body’s normal potassium balance. Some conditions or medications, such as those that might involve or affect the kidneys, might cause the body to eliminate sodium while holding on to its potassium. For example, some medications for high blood pressure do this. If this were the case, the dietary intake of high-potassium foods might need to be monitored.

If, on the other hand, potassium were low, your physician might tell you to adjust your diet, or to take a potassium supplement.

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.