DEAR DR. BLONZ: I take vitamins with dinner, along with a 1,000-milligram calcium pill. I had thought this was the best way to get my daily requirements, but now I hear that we only absorb 500 mg at a time. Is that true? How do you recommend getting one's calcium? -- D.T., Phoenix

DEAR D.T.: There is a specific mechanism by which calcium gets absorbed from the digestive tract, and the 500 mg at a time max is a reasonable approach. It turns out that on average, the human body only absorbs about 20 to 30 percent of the calcium it ingests. This can rise to 50 to 60 percent during adolescence, pregnancy and lactation, but these are periods of unusual demand where the body has its absorptive machinery set on "high." All this absorptive inefficiency is taken into account during the setting of calcium dietary requirements for different age groups.

You are probably getting some calcium from your food, but when taken as a supplement, it makes sense to divide it up among two or more meals. Here are some other steps you can take to help increase your absorption of calcium and other minerals.

-- Get adequate amounts of vitamin D. This vitamin is involved in the production of a calcium-binding protein that helps transport calcium through the intestinal wall. Note that your intake of vitamin D doesn't have to be at the same meal as the calcium.

-- Have enough dietary protein, but don't overdo it. An adequate intake of protein is essential, not only because protein is needed for tissue growth and enzyme production, but because calcium tends to form easily absorbed salts with the amino acids in protein. However, excessive intakes of protein can create an acid burden that drains calcium from the body.

-- Lactose can help, as long as you're not intolerant. This carbohydrate found in milk products can enhance calcium uptake. The effect is tied to the activity of lactase, the intestinal enzyme that helps break down the lactose. However, lactose intolerant individuals -- those who don't produce enough of their own enzyme to digest the lactose -- will not realize this particular benefit.

-- Mealtime is best. The acid environment created during digestion helps keep calcium in solution and ready to be absorbed.

-- Keep phytates and oxalates away. Phytic acid, a naturally occurring compound found in the outer hulls of cereal grains, forms an insoluble salt with calcium and other minerals. This doesn't apply to whole-grain breads, as the phytic acid is broken apart during the leavening process. Oxalic acid, found in rhubarb, swiss chard, cocoa and beet greens, also forms an insoluble salt with calcium. If a meal contains any of these foods, make sure that it's not your only calcium-containing meal of the day.

Aside from all these details associated with calcium absorption, it is also important to appreciate that physical activity improves bone mineralization. Staying active helps to keep that calcium in your bones where you want it.

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 am a retired male, 66 years old, 5'9", 142 pounds and take no doctor-prescribed drugs. In your opinion, what is the nutritional value of a daily consumption of 8 ounces of Low Sodium V8 vegetable juice? I try and eat healthfully, i.e. no red meat, but don't always get my veggies. -- M.M., Sun City, Ariz.

DEAR M.M.: No problems with the V8 juice. I encourage people to eat whole foods: These are the packages made by nature that contain all the nutrients and phytochemicals needed for that particular plant to survive amidst the insults and ravages of nature. You lose a bit of these nutrients when you take steps back to processed food, but your vegetable juice has been only minimally processed. This is not to say that all processed foods are bad; read the labels to see what they are made of. The key is to have real foods -- vegetables, fruits and whole grains -- serve as your foundation. With that as a basis for your diet, the door opens to adding other items. I have no problems with red meat following such an approach.

DEAR DR. BLONZ: Is eating beef liver dangerous? -- J.S., Canada

DEAR J.S.: The liver is a remarkably resilient organ and it is endowed with an ability to regenerate. It has an undeserved reputation as a toxic waste dump, and while it does serve as a clearinghouse for unneeded or unwanted substances, it doesn't hold on to these substances. Its job is to take them out of the bloodstream, make modifications where possible and then send them out of harm's way. If, however, there is an ongoing exposure to dangerous compounds, the liver will be in the midst of the battle. Thus, the health of the animal that the liver comes from is key.

For people in good health with an otherwise healthful diet, an occasional serving of liver should not be a problem. A healthful option is to seek out liver and other meats from grass-fed, organically raised cattle and organic, pastured poultry. Seek out a provider that sells in your area, one who follows a stated philosophy of raising his or her animals on healthful pastures without using hormones or feed additives. You can often find such providers at farmers' markets and natural food stores.

DEAR DR. BLONZ: Maybe you can help me with this fiber problem. In the November 2011 issue of the UC Berkeley Wellness Letter, an article on eating vegetables suggested pureeing veggies and including them in other foods. My concern is about getting the maximum amount of fiber out of the veggies. Does pureeing them reduce the amount of fiber, or is it intact regardless of how the veggie is eaten (raw, steamed, pureed, etc.)? -- V.R.C., via email

DEAR V.R.C.: The process of making a puree out of fresh vegetables (or fruits) does not have a significant impact on its fiber content. Of course, this does not apply to juicers where the fibrous portion of the food is discarded.

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 am a computer engineer and I was fortunate to get a job just out of college. It's a great job, but I spend most of my time working in a cramped space. My concern is that I always eat high-calorie convenience food when I am working, such as pizza, hot dogs and hamburgers. I do like the stuff, but I don't want to be headed down a bad road. What should I add to help prevent chronic diseases? -- I.F., San Jose, Calif.

DEAR I.F.: When young, we have a resilience that allows us to feel that we can eat just about anything and not suffer ill effects. Unfortunately, continued imbalances and abuses over the decades do add up, and by the time we reach our later years, we have to live with the cumulative effects.

There is often a covert aspect to chronic disease. A perfect example of this is hypertension (high blood pressure) where, with the exception of elevated numbers on a blood pressure reading, there can often be no signs or symptoms until the disease's damage is done.

Everything we eat does not have to be a paragon of healthfulness. My approach has always been that you can eat most things as long as the rest of your diet fills in gaps and makes things "whole." Add to this a healthful lifestyle and you can have it all.

But now let's pose a few questions. When building or working on a computer, would you choose substandard components? Would you run a computer in an environment where vibration, dust or power glitches could interfere with the operation of the unit? And finally, would you rely on an operating system that was full of buggy subroutines?

The computer programmer adage "garbage in, garbage out" is akin to dietary dogma "you are what you eat," both reflecting that we are only as good as what we put into our systems.

I encourage you to take a close look at the totality of what you eat, as well as what you are not eating. If your workday is limited in its food options, help your situation by starting the day with a high-fiber breakfast cereal with fresh fruit. Try to have a big salad or fresh vegetables with your lunch, but if that's not feasible, be sure to have those greens with dinner. Keep some nuts and dried fruit at your desk for a snack. Stash some yogurt in the office fridge. If possible, go for a brisk walk during a break -- up and down the stairs or around the block, if that's all that's available. Tweaks such as these could turn those workday fast foods into a minor player in your overall diet and provide greater distance between yourself and the risk of chronic disease.

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.