The Xtend-Life brand of vitamins was first launched in 2000 with the goal of producing vitamin supplements that were natural and effective, according to the Xtend-Life website. The company sources its own raw ingredients and uses its own factory to make the vitamins. As with any vitamin supplement, you may experience some side effects when taking them. The Xtend-life multivitamin, called Multi-Xtra, contains ingredients that may cause more serious side effects, however.
The Xtend-Life multivitamin contains a number of additional ingredients beyond your typical vitamins and minerals, including an herb called horsetail. As a source of silicon, horsetail may be part of the supplement to promote bone health. But the Cleveland Clinic warns against using supplements that contain horsetail because they may cause convulsions or hyperactivity. There's also concern that it may cause you to lose potassium.
Any multivitamin may cause an upset stomach. Common symptoms include abdominal pain, nausea, vomiting or diarrhea. However, the Xtend-Life multivitamin contains an ingredient called methylsulfonylmethane, or MSM -- a supplement touted as a pain reliever and anti-inflammatory that's also known to cause diarrhea, according to the Arthritis Foundation. Taking the multivitamin with food or before bed may help improve tolerance.
Although any of the ingredients in the Xtend-Life Multi-Xtra may cause an allergic reaction, if you're allergic to ragweed you may want to think twice before using this multi because it contains marigold as the source for lutein. Common symptoms of a ragweed allergy include sneezing, runny nose or itchy throat. If you're allergic to a different ingredient in the multivitamin, however, you may experience other types of symptoms such as hives, difficulty breathing, swelling around the face or tongue, tightness in the chest, numbness or tingly skin. Contact your doctor right away if you experience any of these symptoms after taking your multivitamin.
Some of the vitamins and minerals in the multivitamin are in doses greater than the recommended dietary allowance. Taking a multivitamin that contains high doses of vitamins may increase your risk of certain diseases. For example, if you have a history of lung cancer, you should not take any supplement that contains beta-carotene, says the Academy of Nutrition and Dietetics. Multi-Xtra does not specify the type of carotenoids that make up the vitamin A in its multivitamin. The vitamin also contains high doses of vitamin E and selenium, which for men may increase risk of prostate cancer, according to Harvard Health Publications.