Supplements include vitamins, minerals, herbs, and other substances meant to support, or supplement, a balanced diet. While they can offer several benefits, there is such a thing as taking too much or too many, which can lead to several serious health problems.
In fact, dietary supplement complications may cause 23,000 emergency room visits in the United States each year, according to some estimates.
Taking high doses of certain supplements may alter how your body absorbs prescription medications. Use caution with supplements if you are currently taking any prescription medications for the following health conditions, for example:
- Heart disease: Vitamin K reduces the effectiveness of blood thinners, such as Coumadin (warfarin). This can raise your risk of blood clotting, which may lead to a heart attack or stroke.
- Cancer: Vitamins C and E may interact with certain cancer treatments. Avoid taking any additional supplements without discussing them with your cancer care team.
- Depression: Taking St. John’s wort can affect how your body processes antidepressant medication or other drugs, making them less effective in treating your symptoms. When combined with antidepressants, St. John’s wort can also increase your risk of serotonin syndrome, a potentially deadly condition when you have too much serotonin in your body.
Vitamin toxicity can occur when excessive amounts of a vitamin build up in your body. This can happen when you take large or frequent doses of vitamins or supplements. Signs of vitamin toxicity of common vitamins and minerals may include:
- Vitamin A: Irritability, fatigue, nausea, liver damage
- Calcium: Nausea, vomiting, confusion, muscle weakness
- Vitamin D: Nausea, vomiting, constipation, weakness, high blood pressure
- Iron: Constipation, nausea, stomach pain, ulcers
- Zinc: Nausea, vomiting, diarrhea, cramping, low blood pressure, rash
Some supplements may cause uncomfortable digestive symptoms, such as nausea, vomiting, diarrhea, or cramping. Taking high doses of the following supplements may upset your stomach:
- Folic acid
- Iron
- Magnesium
- Vitamin C
- Zinc
Some medications and supplements may damage your kidneys. This pair of organs is responsible for filtering and excreting drugs from your body. Taking too many supplements or very high doses of certain supplements, including licorice root and St. John’s wort, may cause damage. This is especially true if you already have kidney disease.
A 2016 study also found that taking too much vitamin C may increase the risk of kidney stones in some people.
Many adults can take their daily supplements safely and without serious health complications. To ensure that your supplement plan is safe, consider the following steps:
- Talk with your healthcare providers: Give your doctor or pharmacist a complete list of your medications, vitamins, and supplements. They can help you understand your risk of any potential interactions. Doing so is especially important before surgery or any medical procedures.
- Follow the dosage recommendations: Do not exceed the recommended dosage for any of your medications, vitamins, or supplements.
- Monitor for side effects: If you experience any unwanted health changes after starting a new supplement, stop taking it and talk with your doctor.
- Use caution during pregnancy: If you’re pregnant or breastfeeding, it’s important not to take any supplements other than a prenatal vitamin without discussing them with your doctor first.
