Mark Twain jokingly — or maybe not — once said: “Too much of anything is bad, but too much whiskey is barely enough.” We all know the health benefits of a little alcohol and the health risks of imbibing indiscriminately, but experts say you can also get too much of a good thing, like minerals, vitamins, and other dietary supplements. “Overdosing on vitamins and minerals can make people very ill and lead to deadly conditions over time," says Dr. Tod Cooperman, founder and president of ConsumerLab.com.
“In my experience, the most common cause of injury from dietary supplements, and even healthful foods, is when people overdo it,” Cooperman tells Newsmax. “They get excited by the prospect of a benefit and then go overboard. Unfortunately, the negative effects can be slow to recognize. There are cases of people who drink only green tea instead of water who develop fluorosis because green tea contains fluoride. Their teeth and bones become brittle.”
Dr. Christine Le, a family medicine specialist from Kelsey-Seybold Clinic in Houston, says that while vitamins and supplements are a billion dollar industry, people trying to get healthier may be ingesting more than they need.
“People combine multivitamins with additional vitamin supplements that duplicate what’s already in the multi,” she tells Newsmax. “For many people who are taking prescription medications, these additional supplements may interfere with the absorption of their medication or cause their kidneys and livers to work harder. So, it’s important to check with your health care provider for recommendations prior to starting any natural supplements to determine if they are safe for you.”
Here are some examples:
Fiber. Americans are advised to increase their intake of fiber to help reduce the risk of some cancers, reduce bad cholesterol, and help with daily elimination, says Dr. Le. “However, if there is too much fiber in the diet, or you are adding supplementation, this could lead to abdominal bloating, and extreme gas pain.
B-6. Vitamin B-6 has been shown to help people with inflammatory conditions, irritable bowel syndrome (IBS), and Crohn’s disease. It is also useful for optimal cognitive function and improves sleep. However, in 2016 the Food and Drug Administration reduced the recommended daily value of B-6 to 1.7 mg and 1.5 mg respectively for men and women, notes Cooperman. Higher doses of B-6 can cause nerve damage, skin lesions, and increase the risk for hip fractures. One clinical study found that taking 25 mg of B-6 daily as part of a B-complex vitamin was shown to increase the risk for heart attack, stroke and death in diabetes patients with advanced kidney disease.
Vitamin D. This important vitamin along with calcium can help increase bone density in people who are deficient. It has also been linked to a reduced risk of heart attack and stroke, reduced risk of asthma and allergy and less inflammation. High levels can result in hypercalcemia, or too much calcium in the blood. The symptoms include confusion, constipation, weakness, loss of appetite and painful calcium deposits, according to ConsumerLab.com. An annual blood test can determine whether you are deficient in vitamin D and if you need supplementation.
Vitamin A. This fat-soluble vitamin is essential for maintaining good vision and healthy skin, and also helps boost the immune system. One study showed that it enhanced the healing rate, and improved vision, after laser eye surgery when taken along with vitamin E. Cooperman says that there is mixed evidence that the use of vitamin A can reduce the risk for certain cancers, such as breast cancer and melanoma, a deadly skin cancer. Too much vitamin A can pose a risk for pregnant women because in dosages greater than 1,500 mcg it can cause birth defects. Excessive dosages of this vitamin have also been associated with abnormalities in the liver, central nervous system, bones, and skin. Long-term use of supplementation was linked to increased risk for lung cancer, so those who smoke are discouraged from taking the vitamin. A review of clinical studies also showed a slight increase in mortality for people taking high doses—more than 1,500 mcg to 3,000 mcg of vitamin A.
For more information on nutrients and their safety, ConsumerLab.com has a free table indicating which vitamins and minerals have an Upper Tolerable Intake Level.