Some Michigan residents have turned to supplements this cold and flu season to boost their body’s defenses.
While vitamins can help boost the immune system, too much of a good thing can have negative effects, explained Sarah Hutchinson, registered dietitian at Henry Ford Health.
“Supplement toxicity is where you get too many vitamins or minerals, usually from supplements or artificial sources,” she said. “This is increasingly becoming an issue with more readily available supplements.”
It is very rare for individuals to consume a toxic amount of a given vitamin or mineral from dietary sources alone. But adding one or more supplements can lead to consumption hundreds or thousands of percentage points beyond what is recommended daily.
As an example, Hutchinson described a situation where a patient might take a daily multivitamin, plus a daily dose of a vitamin C supplement like Emergen-C, a zinc supplement, and an elderberry supplement that also includes zinc. and vitamin C.
“They take one product over another when they probably only need this multivitamin every day or every other day,” she said. “I heard a good metaphor recently: if you put more gas in a car, it won’t go any faster. Similarly with vitamins and minerals, just because we have more of them doesn’t mean your body will perform better.
Symptoms of excessive intake of a vitamin or mineral can be general or non-specific, such as headaches, stomachaches, or racing heart. More serious reactions may include blood clots and stroke-like symptoms, especially in people with liver or kidney problems.
Too much of one nutrient can also look like a deficiency of another, making it difficult to self-diagnose the problem. A blood test can help assess unhealthy levels; the same goes for better evaluating food labels when determining which supplements to take.
The required nutrients listed on the typical Nutrition Facts label have undergone a change in recent years to reflect nutrients that many Americans do not get enough of. Labels should still include calcium and iron, but instead of requiring vitamins A and C, they now require vitamin D and potassium.
When possible, dietitians suggest foregoing supplements in favor of a nutrient-dense diet; citrus fruits and broccoli, for example, are good sources of vitamin C. Supplements should only be used when there are deficiencies, such as if you are having trouble getting enough of a given nutrient naturally.
Hutchinson also recommends avoiding supplements that far exceed daily recommendations. A good route is to discuss nutritional options with a primary care physician to better determine which ones to take and whether a supplement might negatively interact with another medication.
For example, the United States Food and Drug Administration warns that drugs for HIV/AIDS, heart disease, depression, organ transplant treatments and birth control pills are less effective when combined with a herbal supplement known as St. John’s Wort. Also, the combination of multiple blood thinners, including a vitamin E supplement, may increase the risk of internal bleeding or stroke.
Since the average American diet “has room for improvement,” Hutchinson said there’s generally nothing wrong with taking a multivitamin. But some are better than others.
“The best rule of thumb is to make sure you don’t get more than 100% of (the recommended daily allowance),” she said. “It’s more helpful to take smaller doses instead of getting 100% all at once.”
Learn more about MLive: