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Prenatal vitamins can help provide the building blocks — nutrients — your body needs to grow and develop a new little human, and keep you healthy.

But even good, nourishing things can come with a few hiccups.

You may not have been… well, regular, since you started taking prenatal vitamins. Or maybe you’ve noticed other symptoms, like you’re always really itchy.

You’re not imagining it — prenatal vitamins can sometimes cause minor side effects.

So, what’s in prenatal vitamins? And why do they sometimes cause annoying side effects? Here’s what to know about prenatal vitamins and side effects and what you can do about them.

Some common prenatal vitamin side effects are also common side effects of pregnancy. This means that sometimes you might not know if your prenatal vitamins are causing the hiccups (including the literal ones when you feel like you might vomit).

Prenatal vitamin side effects may be even worse when you’re pregnant than when you’re not. But some people may not get any vitamin side effects at all.

Below is a list of common prenatal vitamin side effects and some of their causes:

Digestive discomforts

Prenatal vitamins include iron because your body needs this mineral to make lots of red blood cells to carry oxygen to you and your baby. While iron gets your blood flowing, it can clog up the digestive pipes a bit.

Along with constipation — a very common complaint — you might have other gut-related side effects like:

  • stomach cramps
  • upset stomach
  • bloating
  • gas
  • hard or small bowel movements
  • tarry or dark-colored bowel movements

Skin and hair changes

Certain vitamins can cause common hair and skin side effects.

Side effectMay be caused by:
hair lossvitamin A
skin dryness or peelingvitamin A
skin itchinessvitamin A or fillers in prenatal vitamins
easy bruisingvitamin E
skin rashvitamin E

Other aches, pains, and changes

Iron, calcium, iodine, and other minerals in prenatal vitamins can sometimes cause side effects including:

  • hives
  • stomach bleeding
  • teeth staining
  • muscle weakness

These minerals can also be fully or partially responsible for some effects that are also common in pregnancy:

  • sore teeth and gums
  • stomach irritation
  • fast or uneven heart rate
  • urinating more often
  • not being able to focus — also known as “pregnancy brain” because your body is super-multitasking!
  • confusion (see above)
  • appetite loss
  • more mouth watering — or is eating for two just making you hungrier?

Other side effects that can happen when you’re pregnant may be made worse by prenatal vitamin side effects. These include:

Other risks

Too much of a good thing can be harmful to your health. It’s completely possible to take too many or too high a dose of prenatal vitamins.

You also need to be aware of vitamins and minerals in other supplements or products you use. Too much of some vitamins and minerals can be dangerous for you or your baby.

For example, while too little vitamin A can cause poor eyesight, too much of this vitamin can be toxic for you and your baby. Too much vitamin A can harm your liver and may lead to some birth defects in baby.

Tell your doctor if you’re taking or using any kind of vitamin, medication, or creams. Avoid all vitamin A products while you’re pregnant, even skin creams.

Check for vitamin A ingredients like:

  • tretinoin
  • isotretinoin
  • retin-A

In fact, you can overdose on vitamins A, D, E, or K. These vitamins stay in your body for a long time and too much can be serious for you, and also harm your growing little one.

Other nutrients in prenatal vitamins like some minerals may also cause serious side effects if you take too much. Get urgent medical attention if you think you’ve taken too many supplements or have serious side effects.

Tell your doctor about all the medications you’re taking. Prenatal vitamins can have negative interactions with some over-the-counter and prescription medications, like:

Prenatal vitamins are also called prenatal supplements because they contain vitamins along with minerals and other nutrients you and your growing baby need.

Doctors recommend that women of child-bearing age take prenatal vitamins even if they’re not planning to get pregnant — just in case.

While our bodies absorb the best kinds of nutrients from the foods we eat, let’s face it, everyone isn’t always able eat the best variety of food or very much fresh food every day.

When you’re pregnant and suffering from nausea or aversions, it can be even harder to get your 5 fruits and veggies a day!

Plus, you may not know you’re pregnant for weeks or longer. From the very first month of pregnancy, lots of important baby stuff is developing, like the brain and spinal cord. This is why taking a prenatal vitamin has you and your baby covered!

For example, folic acid in a prenatal vitamin is needed to help your baby grow a healthy spinal cord and nervous system. Vitamin A is needed for healthy eyes. Too little of this vitamin is a leading cause of blindness in babies around the world.

Prenatal vitamins can help fill nutritional food gaps and make sure you and your baby have all the vitamins and minerals you need for a healthy pregnancy and birth. They can even help keep you healthy after your delivery while you breastfeed.

Not all prenatal vitamins are the same. Different formulations may have slightly different dosages of some nutrients. Ask your doctor about the best one for you.

All prenatal vitamins are made for pregnant people and normally include:

  • folic acid or folate
  • vitamin A
  • vitamin C
  • vitamin D
  • vitamin E
  • vitamin K
  • vitamin B12
  • iron
  • calcium
  • copper
  • zinc
  • magnesium

Remember: the benefits of prenatal vitamins outweigh the side effects — as long as you take them exactly as directed.

Ask your doctor about the best prenatal vitamins for you and your baby.

Try these tips to avoid or reduce side effects from prenatal vitamins:

  • Take your prenatal vitamin regularly and in the exact prescribed dosage.
  • Avoid taking other multivitamins, vitamins, supplements, or herbal remedies while you’re taking prenatal vitamins and especially when you’re pregnant.
  • Don’t take a prenatal vitamin on an empty stomach — take prenatal vitamins with food or after a meal.
  • Drink a full glass of water to wash down a prenatal vitamin.
  • Swallow the prenatal vitamin whole. Do not chew, cut, break, crush, or open a prenatal vitamin.

Ease constipation with these remedies

  • Drink plenty of water with your prenatal vitamin.
  • Add more fiber to your diet, like whole grains, oats, and fresh fruit and veggies.
  • Add natural prebiotics and probiotics to your diet, like yogurt, bananas, and onions.
  • Ask your doctor about taking other supplements that help ease constipation, like fish oil and probiotics.
  • Try a prenatal vitamin with less iron in it.
Was this helpful?

If you’re getting a lot of side effects, like itching and stomach irritation, the fillers or additives in some prenatal vitamins might just not suit you. Ask your doctor about switching to a different kind or brand of prenatal vitamin.

Prenatal vitamins are very important for a healthy pregnancy and baby. This is why doctors recommend taking them well before you plan on getting pregnant.

Prenatal vitamins can sometimes cause minor but annoying side effects. These can be worse when you’re pregnant because some of them are the same as common pregnancy side effects.

Prenatal vitamin side effects aren’t serious and can normally be managed with home remedies and changes in your diet.

Tell your doctor if you have serious prenatal vitamin side effects. Taking too many prenatal vitamins or other supplements can be harmful for you and your growing baby. Check with your doctor before taking any new supplements.