Consumer Reports: When it a good thing too much?
Most American adults already get enough calcium, folic acid and iron without eating fortified foods or taking dietary supplements, according to Consumer Reports.
Here's what you need to know about getting the right amount of those nutrients.
Adults generally need 1,000 to 1,200 milligrams of calcium per day, which is plentiful in dairy and also found in beans, greens, fruit and nuts. But don't routinely exceed 2,000 to 2,500 milligrams, particularly of added or supplemental calcium, which research suggests is handled differently by our bodies than the calcium from food.
Too much added calcium can increase the risk of kidney stones. In contrast, food that's naturally rich in calcium seems to lower that risk. Calcium dietary supplements can also interact dangerously with some heart and thyroid drugs.
It's easy to go overboard, Consumer Reports notes. A 3/4-cup serving of Total Whole Grain cereal, for example, has 1,000 milligrams of calcium, and a Special K French Vanilla Protein Shake contains 350 milligrams. Add two Nature's Way Alive Calcium Gummies (1,000 milligrams), and you've consumed more than double the daily requirement.
Folic acid and folate
The Institute of Medicine (IOM) recommends that most adults consume 400 micrograms of folic acid per day, a vitamin you'll find in dark leafy greens, fruit, beans and eggs. But don't get more than 1,000 micrograms of folic acid per day, a form of folate used in dietary supplements and fortified foods.
Too much can mask vitamin B12 deficiency, most likely to be seen among people 50 and older, and in vegetarians. "Untreated, that can lead to nerve damage, cognitive trouble and even psychiatric problems," says Consumer Reports' medical director, Dr. Orly Avitzur.
Research suggests that daily folic acid supplements of 300 to 800 micrograms can hide the symptoms of B12 deficiency. In a study of more than 2,500 older adults, consumption of more than 400 micrograms per day was associated with cognitive decline.
Many manufacturers add folic acid to such products as enriched bread, cereal, flour, pasta and rice.
If you snack on a Luna bar and take a One A Day Men's 50+ Healthy Advantage supplement, you've consumed double the amount that your body requires and hit the government's safe upper limit.
In general, 8 to 18 milligrams of iron per day is sufficient unless you have a condition like iron deficiency anemia. The IOM says healthy people shouldn't exceed 45 milligrams. More than that can increase the likelihood of diabetes and heart problems for those with hemochromatosis, a surprisingly common genetic condition that causes the body to deposit excess iron in vital organs.
Most adults can get sufficient iron from food that naturally contains it, including red meat, beans, broccoli and eggs.
Cereal, pasta and bread are often fortified with iron, so you might get more than you need without even realizing it. One serving of Total Raisin Bran provides 18 milligrams; one GNC Ultra Iron supplement contains 65 milligrams.
What to do
It's tough to avoid fortified foods altogether, nor should you. But it's wise to concentrate on getting as much of your calcium, folic acid and iron as you can from whole food sources rather than fortified products. Consumer Reports recommends checking the Nutrition Faces label on packaged goods to see how much of those nutrients you're getting. And unless your doctor has recommended dietary supplements of calcium, folic acid or iron, skip them.
To learn more, visit ConsumerReports.org.
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