Are You Getting These Nutrients? - Part 9

Our bodies use calcium in so many ways; it's hard to list them all. Of course, we know about bone health. It's also vital for the functioning of our muscles and nerves, and maintaining the correct acid/base balance.

Low-carb sources include dairy products, sardines, canned salmon, tofu, and (as in almost everything) greens.

Calcium is the most abundant mineral in your body. It is essential for the development and maintenance of strong bones and teeth, where about 99% of the body's calcium is found. Calcium also helps the heart, nerves, muscles, and other body systems work properly. It is probably best known for helping prevent osteoporosis.

Your body needs several other nutrients in order for calcium to be absorbed and used properly, including magnesium, phosphorous, and especially vitamins D and K. Many factors, including age, disease states, and medications, can affect calcium absorption. Carbohydrates may enhance calcium absorption while coffee and cigarette smoke may impede it.

The best way to get calcium is through food. Many foods are fortified with calcium. But, some people may need to take calcium supplements to get the recommended amount. It is especially important for children to get enough calcium in their diets as they are growing and forming bone, and for older people as they start to lose bone.

Postmenopausal women, people who consume large amounts of caffeine, alcohol, or soda, and those who take corticosteroid medications may need calcium supplements. Calcium deficiency can be found in people who don't absorb enough calcium, as can happen with Crohn's disease, celiac disease, and some intestinal surgeries.

The richest food sources of calcium include:

• Cheeses, such as Parmesan, Romano, gruyere, cheddar, American, mozzarella, and feta
• Low-fat dairy products, such as milk and yogurt
• Tofu
• Blackstrap molasses

Other good sources of calcium include – almonds, brewer's yeast, bok choy, Brazil nuts, broccoli, cabbage, dried figs, kelp, dark leafy greens (such as dandelion, turnip, collard, mustard, kale, and Swiss chard), hazelnuts, oysters, sardines, and canned salmon.

Foods that are fortified with calcium, such as juices, soy milk, rice milk, tofu and cereals, are also good sources of this mineral.

There are many forms of calcium available as dietary supplements. They differ in the amount of calcium they contain, how well the body absorbs them, and how much they cost. The two most popular forms are calcium citrate and calcium carbonate.

• Calcium citrate: Easily absorbed and digested by the body. It does not contain as much elemental calcium -- the amount your body actually absorbs -- as calcium carbonate. It is more expensive than calcium carbonate. Also, calcium citrate should not be used with aluminum-containing antacids.
• Calcium carbonate: Less expensive than calcium citrate and contains more elemental calcium. Requires a certain amount of stomach acid to be absorbed. So, it is usually taken with a glass of orange juice. Many antacids contain calcium carbonate.

Avoid calcium supplements that are derived from oyster shells, dolomite, and bone meal as they may contain lead, a toxic metal that can harm the brain and kidneys, cause anemia, and raise blood pressure.

Calcium supplements should be taken in small doses (no more than 500 mg at a time) during the day with 6 to 8 cups of water to avoid constipation.

The following are daily dietary recommendations from the Institute of Medicine.

Adult

• 19 to 50 years: 1,000 mg
• Women 51 years and older: 1,200 mg
• Men 51 to 70 years: 1,000 mg
• Men older than 70: 1,200 mg
• Pregnant and breastfeeding women under 19 years: 1,300 mg
• Pregnant and breastfeeding women 19 years and older: 1,000 mg

For prevention of colon cancer, some researchers recommend 1,800 mg per day. Speak with your doctor to determine the right dose for you.

Take dietary supplements only under the supervision of a knowledgeable doctor since there is a potential for side effects. Total calcium intake, from combined dietary and supplemental sources, should not exceed 2,500 mg per day.

Side effects can include constipation and stomach upset. Very high doses can cause nausea, vomiting, loss of appetite, increased urination, kidney damage, confusion, and irregular heart rhythm.

People with hyperparathyroidism, kidney failure, sarcoidosis, or cancer could be at risk for high levels of calcium and should not take calcium supplements.

People with a history of kidney stones should not take calcium supplements. However, some research suggests that calcium in foods may not increase the risk of kidney stones. If you have or have had kidney stones, talk to your doctor about whether you should limit calcium in your diet.

Some population studies suggest that getting high amounts (more than 2,000 mg per day) of calcium through the diet may increase the risk of prostate cancer. Two of these studies found that low-fat and nonfat milk, but not other dairy foods, was associated with a higher risk of advanced prostate cancer. But these studies don't prove that drinking low-fat or nonfat milk causes an increased risk of prostate cancer. And some research suggests that the amount of calcium in the diet isn't associated with prostate cancer risk. If you have prostate cancer, or are concerned about dairy products and prostate cancer risk, talk to your doctor.