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Many people assume that nothing bad can come from taking vitamins. After all, they are found naturally in healthy foods, so how could they be unhealthy in pill form? While perhaps not unhealthy, it is possible to overdo it on the supplements\u2014and knowing the signs you\u2019re taking too many vitamins can help you pause and reevaluate your regimen if needed.<\/p>\n
\u201cPeople think of supplements in the same way they do fruit,\u201d said Robert J. Fontana, M.D.<\/a>, professor of medicine at University of Michigan Medical School. \u201cThey think, cranberries or grapes can\u2019t make me sick, so if I consume more of them, I\u2019ll get healthier.\u201d And yet, this isn\u2019t always the case. Taking too many vitamins and supplements<\/a> can come with risks.<\/p>\n Meet the experts: Robert J. Fontana, M.D.<\/a>, professor of medicine at University of Michigan Medical School; Cindy Reuter, N.D., M.S.O.M., M.P.H., LA.c<\/a>., medical director of integrative medicine at Dartmouth Health Alice Peck Day Memorial Hospital in Lebanon, NH; Pieter Cohen, M.D.<\/a>, associate professor of medicine at Harvard Medical School and leader of the Cambridge Health Alliance Supplement Research Program in Cambridge, MA; Olivia Thomas, M.S., R.D., L.D.N.<\/a>, director of nutrition innovation and implementation at Boston Medical Center.<\/p>\n The best way to avoid these risks? Talk to your healthcare provider before adding anything new to your routine. \u201cThe number one thing to do is to talk to your doctor,\u201d affirmed Pieter Cohen, M.D.<\/a>, associate professor of medicine at Harvard Medical School and leader of the Cambridge Health Alliance Supplement Research Program in Cambridge, MA. And yes, it\u2019s still important to do so even if you\u2019ve done your own research to find out if magnesium can improve sleep<\/a> or if vitamin C or vitamin E does more for your skin<\/a>.<\/p>\n In the meantime, read on to discover the possible signs and side effects of taking too many vitamins, plus the key interactions you should know.<\/p>\n Is it dangerous to take too many vitamins?<\/p>\n To answer this question, you have to know what supplements are really intended for. \u201cSupplements are commercial products marketed for health, but they are not medications,\u201d said Olivia Thomas, M.S., R.D., L.D.N.<\/a>, director of nutrition innovation and implementation at Boston Medical Center. \u201cThe most important thing is to know why you are considering the supplement in the first place. Supplements should fill a specific nutrient gap, not replace a balanced diet or act as a shortcut to better health.\u201d In other words, you should never rely on a supplement exclusively to ensure you\u2019re getting a certain vitamin or mineral\u2014doing so will only make your diet less balanced and healthy overall.<\/p>\n What\u2019s more, vitamins can be dangerous in people with certain medical conditions who need to avoid certain supplements altogether. \u201cBe extra cautious if you\u2019re on any medications and\/or already using other supplements, if you have liver, kidney, or heart problems, if you\u2019re undergoing cancer treatment, if you\u2019re on immune-modifying drugs or blood thinners, or if you\u2019re pregnant, breastfeeding or trying to conceive,\u201d said Cindy Reuter, N.D., M.S.O.M., M.P.H., LA.c<\/a>., medical director of integrative medicine at Dartmouth Health Alice Peck Day Memorial Hospital in Lebanon, NH.<\/p>\n It\u2019s also important to remember that the FDA doesn\u2019t regulate supplements the same way<\/a> it does medications or food. Instead, supplement companies are responsible for testing their products for safety\u2014something that\u2019s hard to confirm. \u201cYou don\u2019t know the quality of the supplement,\u201d Dr. Cohen said. \u201cOften, supplements are not accurately labeled. Avoid supplements with labels that suggest they\u2019ll do anything.\u201d<\/p>\n Signs you may be taking too many vitamins<\/p>\n There are a variety of signs that may show your body is holding onto too high of a dose of the vitamins you are taking. \u201cIt\u2019s important to remember that water-soluble vitamins<\/a>, such as vitamin C and the B-vitamins, are generally excreted in urine when taken in excess, while fat-soluble vitamins,<\/a> such as A, D, E, and K, can build up in the body and pose a higher risk of toxicity if overused,\u201d said Thomas. \u201cMinerals and other supplements can also carry risks, since they play critical roles in many body systems and even small imbalances can disrupt normal function.\u201d<\/p>\n Depending on the supplement or combination of supplements, you may experience a wide range of symptoms. \u201cTaking too much can sometimes look like vague, everyday symptoms,\u201d Thomas explained.<\/p>\n Some signs are specific to certain supplements. If you\u2019re concerned you\u2019re taking too many vitamins or supplements, consult your physician, stat. Wondering what symptoms to look for? Here are strong indicators that your supplement(s) may be doing more harm than good.<\/p>\n 1. Heart palpitations or chest pain<\/p>\n Seek medical attention if you experience any cardiac symptoms, particularly while taking a supplement. \u201cThese products can have a lot of caffeine,\u201d said Dr. Fontana. \u201cThey can raise your blood pressure.\u201d Whether you have an underlying heart condition you either know or don\u2019t know about, it\u2019s important to get these kinds of symptoms checked out. Also, Dr. Fontana noted that if you take calcium channel blockers to lower your blood pressure, herbal supplements may interact.<\/p>\n 2. Skin irritation<\/p>\n \u201cRashes or allergy-like reactions may indicate you\u2019re taking too much of a supplement,\u201d said Reuter. One study in Health Science Reports<\/a> found that allergic contact dermatitis was a possible side effect of taking any vitamins except for vitamin B2 and vitamin B9.<\/p>\n 3. Discolored urine and skin<\/p>\n Thomas said that bright or discolored urine and changes in skin tone can both result from taking too many vitamins. If your urine becomes dark and your skin starts to turn yellow, bring these symptoms to your healthcare provider\u2019s attention right away. \u201cAlthough it\u2019s rare, your supplements could be causing a liver injury,\u201d explained Dr. Fontana.<\/p>\n 4. Dizziness<\/p>\n This can indicate you\u2019ve taken too much iron. \u201cExcess iron intake can lead to liver toxicity,\u201d explained Sue-Ellen Anderson-Haynes, M.S., R.D.N., C.D.C.E.S.<\/a>, spokesperson for the Academy of Nutrition and Dietetics and owner of 360Girls&Women and B.E.A.T. Gestational Diabetes. \u201cSigns of iron overload may also include low blood pressure, a metallic taste in your mouth, and convulsions.\u201d In addition to dizziness, Thomas noted that other neurological symptoms such as headaches, tingling in the hands or feet, and trouble sleeping may also signal a vitamin overload.<\/p>\n 5. GI problems<\/p>\n The Mayo Clinic reports that fiber supplements<\/a> may cause bloating and gas, while too much vitamin C<\/a> may result in diarrhea, upset stomach, and vomiting.<\/p>\n A really good rule of thumb: the goal of supplements is to enhance nutrition, but you shouldn\u2019t notice that it\u2019s happening. \u201cNo supplement should make you start to feel good or bad,\u201d said Dr. Cohen. Any physical change you experience indicates you might need to rethink taking it.<\/p>\n Vitamin and supplement interactions to know<\/p>\n A number of combinations of vitamins and supplements should be avoided. \u201cCalcium and iron compete with each other for absorption, so they should not be taken at the same time,\u201d said Thomas. \u201cAlso, iron and calcium can interfere with the absorption of thyroid hormone replacement medications like levothyroxine<\/a>. Vitamin K can counteract blood thinners such as warfarin<\/a> if taken in high doses. Plus, St. John\u2019s wort<\/a> can also interfere with antidepressants.\u201d<\/p>\n Combining vitamins may also be a hazard, such as \u201cmultiple preparations with B vitamins, vitamin D, and vitamin A,\u201d said Reuter. She also noted that additional combinations to avoid include \u201cmultiple supplements with ingredients that affect bleeding and\/or blood clotting, multiple supplements that have stimulating effects like preparations for focus, alertness, weight loss, and energy, and drug-supplement-herb combos<\/a>.\u201d<\/p>\n