Getting Too Much of Vitamins And Minerals
The health consequences of going overboard.
Subtle Signs You're Getting Too Much continued...
"There might be hints of concern, but they would be very subtle signs," he says.
These fairly mild symptoms may include difficulty sleeping or concentrating, nerve problems such as numbness or tingling, or feeling more irritable -- depending on the nutrient that's going overboard.
The bigger concern, Katz says, is that we're "garnishing the food supply with overfortification."
He says manufacturers have shifted their focus from what they've taken out of food -- such as its fat, sugar, or salt -- to what they're putting in, whether it's vitamin D, probiotics, or omega-3 fats -- whatever nutrient is in vogue.
"When more and more foods are enhanced, it becomes impossible for consumers to know what dose they're getting over the course of a day," Katz says. "Clinicians have to realize we might be introducing new dietary imbalances because of this practice."
Three Nutrients to Watch
Dwyer says vitamin D, calcium, and folic acid are three nutrients you may get too much of, especially through supplements.
Adults who regularly far exceed the 4,000 international units (IUs) daily safe upper limit for vitamin D might may end up with serious heart problems.
Folic acid is added to enriched grain products -- white flours, pasta, rice, breads, and cereals -- to help prevent birth defects in babies due to folic acid deficiency in pregnant women. While folic acid fortification has cut the number of birth defects by 25% to 50%, it might have created other health concerns in people getting too much.
It's not hard to get more than 1,000 micrograms of folic acid a day (the safe upper limit for adults) from fortified foods and supplements on a regular basis. Doing so might hide the signs of a vitamin B12 deficiency in older adults. Vitamin B12 deficiency can sometimes lead to permanent nerve damage if left untreated.
There's no need to worry about foods that are naturally rich in folate.
"Most people can now get enough folic acid without having to rely on supplements," Dwyer says.
In fact, she says, "most people have no problem [with getting too much vitamins or minerals] if they start with food, which is the healthiest and safest way to get them."