What Vitamins and Supplements Should I Avoid During Pregnancy?

Medically Reviewed on 9/15/2021

You should always clear it with your obstetrician before taking any vitamins or supplements while pregnant.
You should always clear it with your obstetrician before taking any vitamins or supplements while pregnant.

Pregnancy is a time to focus on your health and pay attention to what your body needs. You may wonder what vitamins and supplements are healthy during your pregnancy and what to avoid.

This article points out some supplements and vitamins that are better avoided during pregnancy.

Vitamins and mineral supplements that may cause problems

Vitamin A

Vitamin A, also called retinol, helps to maintain your skin and vision. When you’re pregnant, though, taking vitamin A supplements can cause birth defects. Because of this, it is important to avoid taking any supplements or multivitamins other than your prenatal vitamin, that contain extra vitamin A.

Iodine

Iodine is a very important nutrient during pregnancy. It is essential for the proper development of the fetus. However, when taken in excess it can affect thyroid function. Iodine overdose may cause hyperthyroidism or hypothyroidism. Too much iodine may also affect the neurodevelopment of the child.

If you are taking extra vitamin C, vitamin D, or vitamin B6 supplements outside of your prenatal multivitamin, discuss this with your healthcare professional. High amounts can be dangerous.

Herbal supplements to avoid during pregnancy

You should always clear it with your obstetrician before taking any supplements while pregnant.

Following is a list of supplements you should avoid when pregnant. Remember, this list is not exhaustive! It is important to always consult your doctor before taking a supplement, especially when pregnant.

  • Juniper can have negative effects on your pregnancy.
  • Saw palmetto is not safe to use throughout pregnancy and breastfeeding. It can also interfere with your hormones.
  • Yarrow may cause miscarriage.
  • Licorice can affect fetal health.
  • Boldo can harm the fetus and organs.
  • Ephedra has been labeled as having an unreasonable risk by the FDA.
  • Goldenseal can reach the fetus through the placenta, worsen jaundice, and lead to a life-threatening condition.
  • Blue and black cohosh have been known to induce labor.
  • Dong quai may be unsafe, as it may affect the uterus muscles.
  • Pennyroyal can cause miscarriage and has also caused organ failure.
  • Shepherd’s purse can also cause miscarriage.
  • Passionflower can induce labor and uterine contractions.
  • Red clover can interfere with your hormones when pregnant.
  • Yohimbe can cause seizures and heart attacks.

Alternative treatments and drugs

Be cautious of any drugs that you might take when pregnant. Drugs include suppositories, medicines, tablets, oils, inhalants, and ointments. Anything you take may be passed to the baby through the placenta. Medicines have the possibility of causing a birth defect, or congenital malformation. They can impact the baby’s development. Medications can also have a negative impact during labor.

Also make sure to speak to your doctor before using any alternative treatments such as aromatherapy, homeopathic remedies, or massage oils.

Foods and beverages to avoid

Now you know the dangers of taking these vitamins and supplements directly. It is just as important to become aware of foods and beverages high in the same vitamins and other substances that can harm your baby. Among things to avoid while pregnant are foods high in vitamin A: 

  • Livers and liver products such as paté
  • Fish liver oils such as cod liver oil
  • Foods that are supplemented or fortified with vitamin A

Foods with vitamin A such as carrots are safe to eat while pregnant.

You will also want to avoid fish that contains high amounts of mercury. While oily fish is beneficial to you and to the baby’s development, it is not recommended you eat more than 2 portions per week. Many oily fish contain high amounts of mercury, which could harm your baby’s nervous system. These include:

  • King mackerel
  • Bigeye tuna
  • Swordfish
  • Tilefish (Gulf of Mexico)
  • Orange roughy
  • Marlin
  • Shark

Don't overdo green and herbal teas. It is recommended you limit yourself to 4 cups of herbal or green tea per day. Some herbal teas may be harmful. There are not enough studies made to know if a large amount can be harmful to the baby, and caution is recommended. Check with your doctor first.

It is important to talk to your healthcare provider if you are in doubt about the safety of any supplement or food.

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Medically Reviewed on 9/15/2021
References
American Journal of Epidemiology: "Maternal Licorice Consumption During Pregnancy and Pubertal, Cognitive, and Psychiatric Outcomes in Children"

AJP Reports: "Severe Hyponatremia Associated with Use of Black Cohosh during Prolonged Labor and Unsuccessful Home Birth"

Birth Defects Research (Part B): "Preliminary Screening Study of Reproductive Outcomes After Exposure to Yarrow in the Pregnant Rat"

BMC Complementary Medicine and Therapies: "Safety classification of herbal medicines used in pregnancy in a multinational study"

Complementary Therapies in Medicine: "Pregnancy outcomes in psychiatric patients treated with passiflora incarnata"

European Journal of Obstetrics & Gynecology and Reproductive Biology: "Influence of mineral and vitamin supplements on pregnancy outcome"

Experimental Biology and Medicine: "Estrogen and Progestin Bioactivity of Foods, Herbs, and Spices"

Federal Register: "Final Rule Declaring Dietary Supplements Containing Ephedrine Alkaloids Adulterated Because They Present an Unreasonable Risk"

JAMA: "Pennyroyal oil poisoning and hepatotoxicity"

MedicinePlus: "Dong Quai"

Medscape: "FDA Updates Advice on Eating Fish for Pregnant Women, Children"

nct: "Drugs and prescriptions in pregnancy," "Which vitamins to take during pregnancy"

NIH: "Goldenseal," "Yohimbe"

Nutrition Reviews: "Safety and efficacy of supplements in pregnancy"

RBGO Gynecology and Obstetrics: "Use of Medicinal Plants with Teratogenic and Abortive Effects by Pregnant Women in a City in Northeastern Brazil"

Tommy's: "Foods to avoid in pregnancy"

WMW: "Health risks over the Internet: advice offered by "medical herbalists" to a pregnant woman"