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Multiple vitamin overdose

Multiple vitamin overdose occurs when someone takes more than the normal or recommended amount of multivitamin supplements. This can be by accident or on purpose.

This is for information only and not for use in the treatment or management of an actual overdose. DO NOT use it to treat or manage an actual overdose. If you or someone you are with overdoses, call your local emergency number (such as 911), or your local poison center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States.

Poisonous Ingredient

Any ingredient in a multiple vitamin supplement can be toxic in large amounts, but the most serious risk comes from iron or calcium.

Where Found

Many multivitamin supplements are sold over-the-counter (without a prescription).


Below are symptoms of a multivitamin overdose in different parts of the body.


  • Cloudy urine
  • Frequent urination
  • Increased urine amount


  • Dry, cracking lips (from chronic overdose)
  • Eye irritation
  • Increased sensitivity of the eyes to light


  • Irregular heartbeat
  • Rapid heartbeat


  • Bone pain
  • Joint pain
  • Muscle pain
  • Muscle weakness


  • Confusion, mood changes
  • Convulsions (seizures)
  • Fainting
  • Fatigue
  • Headache
  • Mental changes
  • Irritability


  • Flushing (reddened skin) from niacin (vitamin B3)
  • Dry, cracking skin
  • Itching, burning skin, or rash
  • Yellow-orange areas of skin
  • Sensitivity to sun (more likely to sunburn)
  • Hair loss (from long-term overdose)


  • Intestinal bleeding (from iron)
  • Appetite loss
  • Constipation (from iron or calcium)
  • Diarrhea, possibly bloody
  • Nausea and vomiting
  • Stomach pain
  • Weight loss (from long-term overdose)

Home Care

Seek medical help right away. Do NOT make a person throw up unless poison control or a health care professional tells you to.

Before Calling Emergency

Have this information ready:

  • Person's age, weight, and condition
  • The name of the product (ingredients and strengths, if known)
  • Time it was swallowed
  • The amount swallowed

Poison Control

Your local poison center can be reached directly by calling the national toll-free Poison Help hotline (1-800-222-1222) from anywhere in the United States. This national hotline number will let you talk to experts in poisoning. They will give you further instructions.

This is a free and confidential service. All local poison control centers in the United States use this national number. You should call if you have any questions about poisoning or poison prevention. It does NOT need to be an emergency. You can call for any reason, 24 hours a day, 7 days a week.

What to Expect at the Emergency Room

Take the container with you to the hospital, if possible.

The health care provider will measure and monitor the person's vital signs, including temperature, pulse, breathing rate, and blood pressure. Symptoms will be treated. The person may receive:

  • Activated charcoal
  • Blood and urine tests
  • Breathing support
  • X-rays
  • ECG (electrocardiogram, or heart tracing)
  • Intravenous (IV) fluids through a vein
  • Tube placed down the nose and into the stomach
  • Medicines to treat symptoms
  • Medicines to remove iron from the body, if needed
  • Blood transfusions (exchange transfusions), if needed

In severe cases, the person may be admitted to the hospital.

Outlook (Prognosis)

Niacin flush (vitamin B3) is uncomfortable, but lasts only 2 to 8 hours. Vitamins A and D may cause symptoms when large doses are taken each day, but a one large dose of these vitamins is rarely harmful. B vitamins usually do not cause symptoms.

If medical treatment is quickly received, people who have iron and calcium overdoses usually recover. Overdoses of iron that cause coma or low blood pressure can sometimes be fatal. Iron overdoses can have long-term consequences to the intestines and liver, including intestinal scarring and liver failure.


Aronson JK. Vitamins. In: Aronson JK, ed. Meyler's Side Effects of Drugs. 16th ed. Waltham, MA: Elsevier; 2016:435-438.

Theobald JL, Mycyk MB. Iron and heavy metals. In: Walls RM, Hockberger RS, Gausche-Hill M, eds. Rosen's Emergency Medicine: Concepts and Clinical Practice. 9th ed. Philadelphia, PA: Elsevier; 2018:chap 151.

Review Date 7/2/2017

Updated by: Jesse Borke, MD, FACEP, FAAEM, Attending Physician at FDR Medical Services/Millard Fillmore Suburban Hospital, Buffalo, NY. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.