Worried an Excess of Vitamins and Supplements May Be Causing Hair Loss?

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    It turns out our vitamins and supplements can play a role in our hair’s health. Can an excess of certain vitamins cause hair loss? Read on to learn more.

    Can an excess of any vitamins or minerals cause hair loss? What the research shows

    Hair loss is a normal part of any person’s life. If you’ve noticed that you’re suddenly losing a noticeable amount of hair, though, you might be wondering what factors are causing this. It turns out that the vitamins and nutrients we take in play a role in the growth – and loss – of our hair. Let’s take a look at some vitamins that, when taken in excess, can actually cause us to lose hair.


    Selenium is an important trace mineral in your body, required for the synthesis of more than 35 proteins. While the right amount of selenium can contribute to healthy hair growth, excess selenium can indeed contribute to hair loss.

    For people over the age of 14, the recommended dietary allowance (RDA) for selenium is 55 μg. This isn’t too difficult to reach, since many foods, including meat, nuts, and vegetables, are rich in selenium and can easily get you to the daily requirement. If you ingest selenium exceeding 400 μg daily, however you may experience selenium toxicity, one symptom of which is hair loss. One study, for example, found that an outbreak of selenium toxicity resulted in serious hair loss in most patients. Other symptoms of selenium toxicity include nausea, vomiting, nail brittleness, irritability, and foul breath.

    Vitamin A

    Vitamin A is critical for the body, supporting vision and immune function, and is necessary for cell growth and differentiation. The RDA of vitamin A is 700-900 mcg RAE.

    Studies do show that excess vitamin A can contribute to partial hair loss, along with other side effects. Indeed, this has been well established for some time. A 1979 case involving a 28-year-old woman found that her sudden hair loss was caused by vitamin A levels that were well above average; once she stopped vitamin A supplementation, her hair loss problem stopped. In effect, vitamin A can cause your hair follicles to become overstimulated, sending them into overdrive; this causes your hair to reach the end of the growth phase too rapidly and start falling out.

    The key is to get vitamin A at healthy levels, which can normally be achieved through a balanced diet.

    Can any vitamin deficiencies cause hair loss?

    Yes, vitamin deficiencies can also contribute to hair loss.

    Iron is a big one. Iron contributes to hemoglobin production, which then helps to deliver oxygen and nutrients to hair follicles. When you don’t have enough, in other words, your hair won’t grow as efficiently, and you may start to notice that your hair is thinning. Some researchers believe that upping the iron storage in your body can improve hair loss, but the research is not yet conclusive. Postmenopausal women, people eating a plant-based diet, and people taking certain medications are at a higher risk for iron deficiency. Because iron in excess is dangerous for your health, always measure your iron levels with a doctor before undertaking any kind of iron supplementation.

    Some other deficiencies that can possibly contribute to hair loss include vitamin D, zinc, and selenium.

    Other potential causes of hair loss

    Hair loss isn’t always caused by taking too many or too few vitamins. There are several factors that can play a role, including:

    • Hormone imbalances
    • Certain medications
    • Skin or scalp issues
    • Pregnancy
    • Inadequate nutrients

    If your hair loss is troubling you, it’s best to talk to your dermatologist or health care provider. That way, you’ll be able to start figuring out any underlying issues – and come up with a treatment strategy that will work for you.

    How to know which vitamins are right for you

    If you’re trying to figure out which vitamins are right for you, you can’t go wrong talking to your medical provider. You can also take our Care/of quiz. Just answer a few easy questions and we’ll help you figure out which supplements might enhance your life!

    It’s vitally important that when you’re picking out your vitamins, you buy from reputable sources. That means you should buy vitamins that are clinically backed, third-party tested, and labeled with proper dosages. (Care/of vitamins, of course, meet these criteria.)

    Key takeaways

    Hair loss is a normal part of life and you don’t need to let it trouble you. But if you’ve noticed sudden or unexpected hair loss or hair thinning, it might have to do with the vitamins and minerals you are – or are not – consuming. Consuming excess amounts of selenium and vitamin A have been linked to hair loss in numerous studies. Vitamin deficiencies, likewise – especially iron deficiencies – have also been linked to hair loss. You can talk to your dermatologist or health care provider about strategies to prevent hair loss and come up with a plan that works for you.

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    Dr. Carla Montrond Correia ND, CNS
    Medical Content Manager
    Dr. Montrond-Correia is a licensed naturopathic physician and a certified nutrition specialist (CNS). She holds degrees from University of Bridgeport, Georgetown University, and University of Saint Joseph, and supplemented her education with internships in the health and wellness space. She's focused on research, herbal medicine, nutrigenomics, and integrative and functional medicine. She makes time for exercise, artistic activities, and enjoying delicious food.
    Our Editorial Staff
    Freelance Contributor
    The Care/of Editorial Team is made up of writers, experts, and health enthusiasts, all dedicated to giving you the information you need today. Our team is here to answer your biggest wellness questions, read the studies for you, and introduce you to your new favorite product, staying up to date on the latest research, trends, and science. Each article is written by one of our experts, reviewed both for editorial standards by an editor and medical standards by one of our naturopathic doctors, and updated regularly as new information becomes available.