LOS ANGELES (KABC) -- It's no secret that eating a healthy diet filled with essential nutrients is good for you, but Consumer Reports found out you really can get too much of a good thing.
Supermarket aisles are filled with fortified foods including cereal, orange juice, pasta, bread, protein drinks and snack bars.
"If you have too much of some of the nutrients that are in fortified foods and in dietary supplements, it can be harmful," said Lauren Cooper, Consumer Reports' health editor.
Take calcium, or example. The daily recommended amount for adults is 1,000 to 1,200 milligrams.
Say you start your morning with a bowl of Total Whole Grain cereal. Each serving is fortified with 100 percent of your daily calcium needs - and that's without milk.
Add the milk and pop a daily dose of a calcium supplement, and you've doubled the amount of calcium your body needs.
"Too much supplemental calcium can increase your risk for kidney stones," Cooper said.
Too much iron is another concern. Most healthy adults need just 8 milligrams per day. Women under 51 need 18 milligrams, and pregnant women need 27.
A bowl of Kellogg's Product 19 has 18 milligrams, and plenty of other foods are fortified with iron, so you could be getting more than you think.
"Too much increases the risk of diabetes and heart problems and can cause other serious health issues," Cooper said.
Also, keep an eye on folic acid, a synthetic form of folate. Most healthy adults who aren't pregnant need just 400 micrograms of folic acid or folate per day.
"Overdoing it can hide the symptoms of a vitamin B12 deficiency in people over 50," Cooper said.
Most American adults already get enough of these nutrients without eating fortified foods or taking dietary supplements.
Look to dark leafy greens for calcium, iron and folate. Milk, cheese and yogurt are also good sources for calcium and red meat is a good source of iron.
Consumer Reports says you don't need to avoid fortified foods altogether. But it's a good idea to check labels. Also, unless your doctor recommends a dietary supplement, Consumer Reports says it's best to skip them
Consumer Reports is a not-for-profit organization that does not accept advertising and does not have any commercial relationship with any advertiser or sponsor on this site.