Vitamin overdose and pregnancy.

During pregnancy, it is important to get the proper nutrients to foster healthy fetal development. You may be tempted to take a multivitamin in addition to other supplements. However, vitamin overdose can occur when an individual takes more than the recommended daily amount of a vitamin. This can result when taking more than one multivitamin, or when taking individual vitamins in addition to a multivitamin.

While any vitamin can be toxic if taken in large amounts, calcium and iron pose the greatest toxic risks when taken in excess. Taking a multivitamin during pregnancy is important, although it is best to talk with your doctor before taking any additional supplements to avoid overdosing.

Terms to Know:

  • Recommended Daily Allowance (RDA): the recommended vitamin dosage for 97-98% of healthy individuals
  • Tolerable upper intake level (UL): the greatest amount of a vitamin that can be taken daily without risk of negative health effects
  • Adequate intake (AI): when available data is inadequate to determine RDA, estimates are defined experimentally or through observation
  • Vitamin Toxicity: occurs when taking megadoses of vitamin A, B6, C, D, or niacin

Recommended Daily Intake for Vitamins:

  Pregnant Women Breastfeeding Women Upper limit (UL)§
Age (yr) 19-50 19-50  
Folate (μg) 600 500 1000
Niacin (mg NE*) 18 17 35
Riboflavin (mg) 1.4 1.6 ND
Thiamin (mg) 1.4 1.4 ND
Vitamin A (μg) 770 1300 3000
Vitamin B6 (mg) 1.9 2.0 100
Vitamin B12 (μg) 2.6 2.8 ND
Vitamin C (mg) 85 120 2000
Vitamin  D (IU) 600 600 4000
Vitamin  E (mg) 15 19 1000
Vitamin  K (μg) 90 90 ND
Note: Adequate intakes (AIs) are shown in bold type, while recommended dietary allowances (RDAs) are shown in regular type.
*1 niacin equivalent (NE) = 1 mg niacin or 60 mg of dietary tryptophan.
200 IU (international unit) of vitamin D = 5 μg cholecalciferol.
ND = not determinable due to a lack of data (intake should be limited to foods); RAE = retinol activity equivalents (1 µg RAE of preformed vitamin A= 3.33 IU).
Adapted from Dietary Reference Intakes, Food and Nutrition Board, Institute of Medicine. Washington, DC: National Academy Press.

Symptoms of Overdose:

Symptoms of vitamin overdose also include symptoms that are a part of normal pregnancy.  If you suspect a vitamin overdose, note changes in your pregnancy symptoms that might be explained by the excessive vitamins.

Symptoms of a vitamin overdose may include but are not limited to the following:

  • Cloudy urine
  • Frequent urination
  • Constipation
  • Diarrhea
  • Appetite loss
  • Nausea
  • Stomach pain
  • Muscle weakness
  • Muscle, joint, or bone pain
  • Yellow-orange tint to the skin
  • Sensitivity to the sun
  • Itching or rash
  • Headaches
  • Fatigue
  • Mental or mood changes
  • Rapid or irregular heartbeat
  • Eye irritation or sensitivity to light
  • Cracking lips

If you think you may have overdosed on a multivitamin or supplement, it is important to contact a medical professional immediately. Do not make yourself throw up unless instructed to do so by a health care professional.

Before calling, be prepared to answer the following questions:

  • What is your individual’s age, weight, and condition?
  • What is the name of the product?
  • What time was the product taken?
  • How much was taken?

You can call the National Poison Control Center’s 24-hour helpline at 1-800-222-1222. It does not need to be an emergency to call. You are welcome to call for any question or concern related to overdosing or poisoning.


Vitamins and supplements are not one of those things where more is better. The American Pregnancy Association recommends that you follow your healthcare provider’s prescription or the directions on your prenatal vitamin bottle. Too much of even a good thing can be a bad thing.

Reprinted from