Which vitamin causes metallic taste? A guide to supplement side effects

January 12, 2026 •

4 min read

According to research, many people who take supplements experience an altered sense of taste, including a temporary metallic flavor. This unpleasant sensation, known as dysgeusia, can often be linked to a specific mineral found within a vitamin supplement, rather than the vitamin itself.

Quick Summary

Several minerals in supplements, such as iron and zinc, are known to temporarily alter taste perception, resulting in a metallic flavor. Both a deficiency and an overdose of certain nutrients can be the root cause. The effect is often short-lived as the body processes the supplement.

Key Points

Mineral Content: The metallic taste from supplements is often caused by minerals like zinc, iron, and copper, not the vitamins themselves.
Iron is a Common Culprit: Iron supplements, especially those for anemia or in prenatal vitamins, frequently cause a metallic taste.
Zinc's Dual Role: Both an overdose of zinc (common in cold lozenges) and a deficiency can cause taste alterations.
Vitamin B12 Connection: A deficiency in Vitamin B12 can impair nerve function, leading to a metallic taste.
Usually Temporary: For most supplements, the metallic taste is a temporary side effect that disappears as the body absorbs the nutrients.
Overdose Risk: Taking excessively high doses of minerals like selenium or vitamin D can also result in a metallic taste and other severe symptoms.

Supplements Rich in Minerals are Often the Cause

While the question is 'which vitamin causes metallic taste,' the real culprits are most often the mineral components found in multivitamin and mineral supplements. Metals like iron, zinc, and copper are essential for bodily functions, but when absorbed, their ions can react with salivary proteins, creating a distinct metallic or coppery flavor. This is particularly noticeable with larger doses or certain formulations. For many, this is a harmless and temporary side effect.

The Impact of Iron Supplements

Iron is one of the most common causes of a metallic taste, especially in supplements used to treat anemia or in prenatal vitamins. The taste mirrors that of blood, which is rich in iron-carrying hemoglobin. The unpleasant sensation typically dissipates as the body absorbs the supplement. For some, the taste is so strong it leads to supplement aversion. Different forms of iron, such as ferrous bisglycinate, are sometimes better tolerated with fewer gastrointestinal or taste side effects.

Zinc: A Double-Edged Sword for Taste

Zinc plays a crucial role in maintaining your sense of taste and smell. However, it can cause problems in two ways:

Excess Zinc: High doses of zinc, common in cold lozenges or liquid supplements, can cause dysgeusia, including a metallic taste. This happens when the mineral is absorbed and processed by the body.
Zinc Deficiency: A deficiency in zinc can also impair taste perception, leading to a persistent metallic or odd taste. This is because zinc is essential for an enzyme called gustin, which is vital for the renewal of taste bud cells.

Other Mineral Contributors: Copper and Chromium

Multivitamins can also contain other metallic minerals that contribute to an altered taste. Copper and chromium are two such examples. While necessary in trace amounts, high intake can lead to a metallic aftertaste. Copper toxicity, a more serious condition, also lists a metallic taste as a potential symptom.

What About B-Vitamins?

While less common than mineral issues, certain B-vitamin imbalances can affect taste. A deficiency in Vitamin B12, for example, can cause nerve damage that alters taste perception. Conversely, some people taking high-dose B-complex vitamins have reported dysgeusia as a side effect.

Comparison of Common Supplement-Related Taste Changes


Supplement/Condition	Cause of Metallic Taste	Duration	Common Workarounds
Iron Supplements	Iron salts reacting with saliva; mirrors the taste of blood.	Temporary; lasts shortly after taking the pill.	Take with food, chew gum, or try a different iron form.
Zinc Supplements (High Dose)	Excess zinc being processed by the body.	Temporary; typically subsides after absorption.	Reduce dose or switch to a lower concentration.
Zinc Deficiency	Reduced function of gustin, an enzyme for taste buds.	Persistent until deficiency is corrected.	Address the deficiency through diet or supplementation.
Multivitamins	Combination of metallic minerals like iron, zinc, and copper.	Varies based on dose and content; often temporary.	Take with a meal, stay hydrated, or change brands.
Vitamin B12 Deficiency	Nerve damage affecting taste pathways.	Ongoing until the deficiency is treated.	Correct the deficiency with supplements or injections.

Managing and Preventing a Metallic Taste

For many, the unpleasant flavor is a temporary inconvenience. Here are some strategies to manage it:

Consider the source: If you've just started a new supplement, that's a likely culprit. Check the ingredients, especially for high concentrations of iron, zinc, or copper.
Take with food: Taking supplements with a meal can help reduce the direct interaction of minerals with saliva and minimize side effects.
Hydrate and mask the taste: Drinking plenty of water or chewing sugar-free gum after taking the pill can help wash away the taste. Citrus drinks, like lemon juice, can also help.
Check dosage: Ensure you are not exceeding the recommended daily allowance for minerals, as excess intake is a common cause.
Rule out other causes: If the metallic taste persists or you are not taking supplements, consult a doctor to rule out other medical issues such as infections, poor dental hygiene, pregnancy, or medication side effects.

If the metallic taste becomes a persistent or bothersome issue, and you suspect your supplements are the cause, it is wise to consult a healthcare professional. They can help determine if the dosage is correct or if an alternative formulation is needed. You can find more information about the causes of dysgeusia from reputable health sources like WebMD.

Conclusion

While the term 'vitamin' is often used, it's typically the mineral components, particularly zinc, iron, and copper, that cause a metallic taste when taken in supplement form. Both deficiency and excess of certain nutrients can cause this side effect, which is usually temporary and resolves as the body absorbs the mineral. By identifying the likely culprit, checking dosages, and implementing simple strategies like taking supplements with food, most people can manage or eliminate this unpleasant sensation.

Frequently Asked Questions

Yes, multivitamins are a very common cause of a metallic taste. This is typically due to the metallic minerals they contain, such as iron, zinc, copper, and chromium.

You can try several methods, such as taking the supplement with food, chewing sugar-free gum, drinking plenty of water, or rinsing your mouth with a baking soda and water solution before meals.

In most cases, the metallic taste caused by supplements is a temporary and harmless side effect. However, if it persists or is accompanied by other symptoms, it's best to consult a healthcare professional to rule out a deficiency, overdose, or other medical issues.

Yes, deficiencies in certain nutrients like zinc and Vitamin B12 can cause a metallic taste. For example, zinc deficiency affects the enzymes necessary for proper taste perception.

Iron supplements commonly cause a metallic taste because the iron salts in them can react with saliva. The taste is often compared to the metallic flavor of blood, which is high in iron.

Yes, prenatal vitamins can cause a metallic taste. They often contain high levels of iron, which is a known cause of dysgeusia, especially during the first trimester of pregnancy due to hormonal changes.

While rare, an overdose of Vitamin D can cause a condition called hypervitaminosis D. One of the symptoms of this is a metallic taste, along with nausea and frequent urination.

A deficiency in Vitamin B12 can lead to nerve damage that affects taste buds and the nervous system, potentially causing a metallic taste. High-dose B-complex supplements have also been associated with dysgeusia in some cases.