Can Vitamins Cause Hives or A Skin Rash?
Diet & NutritionNutrients & Supplements

Can Certain Vitamins Cause Hives or Skin Rashes?

Can Certain Vitamins Cause Hives or Skin Rashes?
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Updated on October 29, 2025
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While uncommon, it’s possible to get hives or a skin rash from a vitamin supplement. These are typically caused by a mild allergic reaction to an ingredient in the supplement or in rarer cases, the vitamin itself.

What Causes Hives or a Rash From Vitamins?

Hives and rashes are symptoms of a mild allergic reaction.

Hives are itchy, red, swollen welts caused by increased levels of histamine in the top layers of the skin. They can form quickly and appear anywhere on your body.

An allergic rash develops when your immune system mistakenly identifies a substance, like food, as dangerous. Your body then releases chemicals to fight the substance, leading to inflammation.

An allergic reaction to a supplement may be due to an inactive ingredient, such as proteins from milk or wheat. It may also be caused by the vitamin itself, although this is rare.

Allergy to Iron Supplements

It’s possible to get a rash from an iron supplement, such as ferrous sulfate, an oral version of iron. Symptoms can include swollen, itchy, red, or burning skin.

An allergic reaction to iron supplements may also be triggered by other ingredients, such as tartrazine (a type of yellow food coloring), sulfites, or milk, soy, or wheat byproducts.

If you think you have an allergy to iron supplements, talk with your doctor. They can recommend allergy testing or prescribe a different supplement with fewer additives.

Can Anemia or Low Iron Cause Hives?

Many people who take iron supplements have a type of iron deficiency called anemia, or low levels of iron in the blood.

While iron supplements can trigger a rash for some people, others may experience hives or a rash from low iron.

An anemic rash can be itchy and usually appears as tiny red or purple dots on the skin, called petechiae.

Contact your doctor if you experience a rash due to iron deficiency. They may prescribe topical steroids or oral antihistamines to treat your symptoms. They may also suggest treatments to address the underlying cause of iron deficiency, such as supplements, dietary changes, or in some cases, a blood transfusion.

Rash From Vitamin C

If you develop a skin rash after taking vitamin C, it may be due to an allergic reaction. Other symptoms of a vitamin C allergy can include:

  • Itching
  • Hives
  • Swelling of the lips, tongue, and throat
Topical vitamin C may also cause allergy-like skin symptoms, such as dryness, itching, and redness. However, this is uncommon.

If you notice any allergy symptoms, like a skin rash, after taking a vitamin C supplement, stop taking the supplement and contact your doctor. They can run tests to determine what part of the supplement you’re allergic to and suggest alternatives.

Vitamin C Allergy vs. Toxicity

When taken at recommended levels, vitamin C is generally safe. Too much can cause digestive symptoms, like diarrhea, nausea, and stomach cramps. However, these symptoms are usually not serious.

In rare cases, too much vitamin C can also lead to the development of kidney stones.

According to the National Institutes of Health, the daily recommended intake for adults is between 75 and 120 milligrams (mg). The tolerable upper limit for vitamin C is between 400 mg and 2,000 mg.

Testing for Vitamin Allergies

If you experience allergy symptoms after taking a vitamin, your doctor may recommend seeing an allergist. They can perform tests to identify which substance is triggering the allergic reaction. These include:

  • Skin tests: These involve injecting small amounts of potential allergens under your skin to check for a reaction. If you’re allergic to any of the substances, your skin will become inflamed, red, and swollen within 15 minutes.
  • Blood tests:‌ These involve drawing a blood sample to test for the presence of antibodies to certain allergens.

Treatment for Vitamin Allergies

Over-the-counter antihistamines, like diphenhydramine (Benadryl), can help reduce mild symptoms of a vitamin allergy. If you experience a rash, topical corticosteroid creams can help relieve the swelling and itching.

If you are diagnosed with an allergy to vitamin supplement, the best way to prevent symptoms is to avoid contact with the supplement.

The Takeaway

  • Hives and skin rashes are caused by a mild allergic reaction. This happens when your body mistakes a substance as dangerous and releases chemicals that cause inflammation.
  • An allergy to a vitamin supplement may be due to the vitamin itself or another ingredient in the supplement.
  • A skin or blood test can help identify the cause of hives or a rash after taking a vitamin supplement.
  • Topical corticosteroids and antihistamines, like Benadryl, can help treat hives or a rash from vitamins.
EDITORIAL SOURCES
Everyday Health follows strict sourcing guidelines to ensure the accuracy of its content, outlined in our editorial policy. We use only trustworthy sources, including peer-reviewed studies, board-certified medical experts, patients with lived experience, and information from top institutions.
Resources
  1. Hives Defined. American Academy of Allergy Asthma & Immunology. July 8, 2024.
  2. Allergic Reactions. American Academy of Allergy Asthma & Immunology. April 22, 2025.
  3. Ferrous Sulfate. Memorial Sloan Kettering Cancer Center. December 12, 2022.
  4. Anemia. Cleveland Clinic. April 16, 2024.
  5. Anemia Rash. Cleveland Clinic. May 2, 2022.
  6. Vitamin C Tablets. Cleveland Clinic.
  7. What Can Vitamin C Do for Your Skin? Cleveland Clinic. December 12, 2022.
  8. Vitamin C: Fact Sheet for Health Professionals. National Institutes of Health. July 31, 2025.
  9. Allergy Testing. American Academy of Allergy Asthma & Immunology. November 13, 2023.
  10. Allergic reactions. MedlinePlus. March 31, 2024.
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Michelle Seguin, MD

Medical Reviewer
Member of American College of Lifestyle Medicine

Michelle Seguin, MD, is a board-certified family medicine, lifestyle medicine, and certified functional medicine physician (IFMCP). She is a practicing physician at Root Functional Medicine, a leading telemedicine practice specializing in personalized, root-cause care.

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Allison Forsyth

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Allison Forsyth is a Seattle-based health and wellness writer. She specializes in translating complex medical and nutritional information into accessible, actionable content for diverse audiences. Her expertise includes nutrition science, diabetes management, fitness optimization, and food safety.

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