Supplements and Deficiencies That Can Cause Metallic Taste in Mouth

Nutrient Shortfalls and Supplements That May Cause a Metallic Taste

Certain vitamins can cause side effects like a metallic taste in your mouth.
Nutrient Shortfalls and Supplements That May Cause a Metallic Taste
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Updated on October 13, 2025
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Our taste buds only detect four basic flavors: salty, sweet, bitter, and sour. But what about when your mouth tastes like metal?

This is a pretty common phenomenon known as dysgeusia, according to a research review. Many things can cause it, but certain vitamins and nutrient deficiencies often play a role in the unpleasant taste.

Read on to learn about the top five nutrient supplements and deficiencies that can lead to a metallic taste in your mouth.

1. Certain Multivitamins

Many people get a metallic taste in their mouth after taking their daily multivitamin. This is because lots of supplements contain metals like zinc, copper, and chromium, which have been known to cause this unpleasant side effect, according to Cleveland Clinic. It’s usually temporary and subsides after the vitamin is fully digested.

2. Iron

If you have anemia — a condition marked by an abnormally low red blood cell count — your doctor may recommend that you start taking iron supplements, according to MedlinePlus. Depending on the severity of your condition, you may either take pills or get iron infusions, which is an IV drip given at the doctor’s office.

Both iron pills and infusions can cause a metallic or coppery taste in your mouth. You may also get other side effects like nausea or constipation, according to StatPearls.

3. Zinc

Sometimes, getting too little zinc from your diet can lead to a metallic taste in your mouth, according to MedlinePlus. Zinc is an essential mineral that helps your immune system run properly. It’s also needed for your sense of smell and taste.

In other words, if you have a zinc deficiency, you might have trouble with your sense of taste, leading to a metallic or “off” flavor in your mouth, according to a research review.

4. Vitamin B12

Vitamin B12 is essential for healthy nerves, brain function, and red blood cell production, according to the National Institutes of Health Office of Dietary Supplements (ODS). But if you don’t get enough from your diet, you may experience changes in your sense of taste.

Studies have found that vitamin B12 deficiency is linked with several oral-health effects. These include a red, swollen tongue, angular cheilitis (sores on the sides of your mouth), and a loss of taste receptors, also known as papillae. As a result, you might notice a change when you eat, like bitterness or a metallic taste.

5. Supplements With Heavy Metals

Because vitamins are not regulated by the U.S. Food and Drug Administration (FDA) in the same way medications are, some vitamins may not contain the highest-quality ingredients. Low-quality products can have additives or contaminants such as heavy metals, which can cause a metallic taste, according to ConsumerLab.com.

When you purchase supplements, always make sure that you’re buying them from reputable manufacturers and that the products have been tested by third parties, like the U.S. Pharmacopeia (USP) and the National Sanitation Foundation (NSF).

The most common heavy metals found in low-quality and untested supplements include lead, arsenic, mercury, and cadmium, according to StatPearls. But studies have found that the amounts of metals present in prenatal vitamin supplements, for example, are not often cause for concern.

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Justin Laube

Justin Laube, MD

Medical Reviewer

Justin Laube, MD, is a board-certified integrative and internal medicine physician, a teacher, and a consultant with extensive expertise in integrative health, medical education, and trauma healing.

He graduated with a bachelor's in biology from the University of Wisconsin and a medical degree from the University of Minnesota Medical School. During medical school, he completed a graduate certificate in integrative therapies and healing practices through the Earl E. Bakken Center for Spirituality & Healing. He completed his three-year residency training in internal medicine at the University of California in Los Angeles on the primary care track and a two-year fellowship in integrative East-West primary care at the UCLA Health Center for East-West Medicine.

He is currently taking a multiyear personal and professional sabbatical to explore the relationship between childhood trauma, disease, and the processes of healing. He is developing a clinical practice for patients with complex trauma, as well as for others going through significant life transitions. He is working on a book distilling the insights from his sabbatical, teaching, and leading retreats on trauma, integrative health, mindfulness, and well-being for health professionals, students, and the community.

Previously, Dr. Laube was an assistant clinical professor at the UCLA Health Center for East-West Medicine and the David Geffen School of Medicine at UCLA, where he provided primary care and integrative East-West medical consultations. As part of the faculty, he completed a medical education fellowship and received a certificate in innovation in curriculum design and evaluation. He was the fellowship director at the Center for East-West Medicine and led courses for physician fellows, residents, and medical students.

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Gord Kerr

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Gordon Kerr has worked in the health care industry for the past 15 years. He holds a diploma in Food and Nutritional Science from CSNN, Canadian School of Natural Nutrition, Vancouver. With his passion for a healthy lifestyle and the desire to help others benefit from proper nutrition and natural remedies, Gordon accepted the international position with CARICOM Regional Food and Nutrition in the Caribbean and moved to Barbados. As well as educating the under-nourished people in the region, Gordon formulated dietary plans to help manage medical conditions including chronic nutrition-related diseases, such as diabetes and hypertension. Now retired, Gord enjoys a quiet life on a small island in the Gulf Islands of B.C.

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