Combining several supplements or taking doses higher than recommended may increase the risk of them causing harm, Kitchin said. Actually, you can't get toxic doses of nutrients through food, but you can get absolutely toxic doses through supplements, Kitchin said. The negative effects of taking two wrong doses of vitamins include headaches, nausea, vomiting, diarrhea, and stomach cramps. Any ingredient in a multivitamin supplement can be toxic in large amounts, but the most serious risk comes from iron or calcium.
This is not a cause for immediate alarm. If you accidentally take two of your multivitamins on the same day, don't freak out, don't worry, nothing will happen to you. It's more about taking an excessive and constant amount of a supplement, even if it's something like calcium, which you know is key to your health. A new study published in the Journal of the American Heart Association found that, while calcium-rich foods may help protect heart health, calcium supplements may increase the risk of plaque building up in the arteries and causing heart damage.
In addition to that, there are other common supplements that, according to experts, can be risky if taken in excess. Yes, really nothing, not with just an extra. It's really just a waste of vitamins. I think you'll excrete most of what your body can't use.
Just don't eat a polar bear's liver. If you eat a polar bear liver, you could be consuming a toxic amount of vitamin A, enough vitamin A to cause death. Always read the label and follow the instructions carefully to avoid unintentionally taking a double dose of vitamins.