Most people don’t realize there’s no real advantage to taking more than the recommended amounts of vitamins and minerals and many don’t recognize there may be disadvantages. While the general theme of our blogs are about eating healthy and the vitamin and mineral content of specific foods, sometimes too much of a good thing can be bad for our health. Routinely getting an overload of vitamins and minerals can hurt you. It is very hard to overdo it from diet alone and rare when combining a healthy diet with a standard multivitamin but is not uncommon if you combine the one or both with other supplements. Let’s explore what is too much of some vitamins and minerals and why.
Vitamin C cannot be stored in our bodies so it’s rare to overdo it on this one but getting more than 2000 mg a day can be harmful. The RDA (recommended daily allowance) is 60 mg but too much on a regular basis can cause nausea, vomiting, diarrhea, stomach cramps, heartburn, headache, insomnia and kidney stones.
Iron can be stored and when consistently getting too much, it builds up in our organs causing severe medical conditions. The RDA for iron varies somewhat depending on age and whether you are pregnant but for most its 18 mg. Getting over 45 mg a day is very harmful to your health and can even cause death unless you suffer from anemia. The side effects come in stages and begin with irritability, lethargy, explosive abdominal pain, diarrhea and vomiting, which can sometimes contain blood. Late stage side effects consist of seizures, a decrease in blood sugar levels, fever and liver damage. Symptoms of liver damage can include bleeding and jaundice, which is a yellowing of the skin and white portion of the eyes. Too much iron may also cause scaring in the stomach and intestines, which can lead to a blockage in the digestive tract. Death usually occurs because of a buildup of iron in the heart, liver and endocrine glands, such as the pancreas.
Zinc is not stored in the body and the RDA for adults is between 8-11 mg. Too much can cause digestive upset, including diarrhea and abdominal pain. Very large doses of zinc — 225 milligrams in a single dose can also cause you to vomit. Too much zinc also interferes with your body’s ability to absorb copper from your diet and some antibiotic medications. If you take zinc supplements in the form of nasal spray, you might experience other side effects. High doses of nasal zinc can affect the nerves in your nose, causing anosmia — a loss of your sense of smell.
Vitamin A can be stored in the body making it easier to overdo it when you have some in reserves for when your body needs it. The RDA is between 700-900 micrograms or 2,300-3,000 IU. When too much is taken you can become sick and skin yellowing can occur. Children are more sensitive to an overdose and too much taken while pregnant can cause severe birth defects.
Selenium is stored in the body and the RDA is 55 micrograms. It is not recommended to take more than 200 micrograms daily. An overdose of selenium may cause bad breath, fever, nausea, and liver, kidney and heart problems. It also greatly increases your risk of skin cancer and diabetes. At high enough levels, selenium could cause death.
While a healthy, balanced diet and daily multivitamin is recommended, it’s important to know the risks of taking vitamin and mi