This article breaks down which supplements are considered safe to take throughout pregnancy and why some supplements should be avoided.

Important supplements in pregnancy

Taking the right nutrients is essential at every stage of life, but it’s very critical during pregnancy, as you’ll need to nourish both yourself and your growing babe.

Pregnancy increases the need for nutrients.

Throughout pregnancy, macronutrient intake needs to grow significantly. Macronutrients include carbohydrates, proteins, and fats.

For instance, protein intake needs to develop from the approved 0.36 grams per pound (0.8 grams per kg) of body weight for non-pregnant women to 0.5 grams per pound (1.1 grams per kg) of body weight.

You’ll want to be incorporating protein in every meal and snack to meet your needs.

The requirement for micronutrients, including vitamins, minerals, and trace elements, increases even more than they need for macronutrients.

While some people can meet this increasing demand through a well-planned, nutrient-dense eating plan, others can challenge it.

You may need to take vitamin and mineral supplements for various reasons, including:

  • Hyperemesis gravidarum: This pregnancy complication is identified by severe nausea and vomiting. It can lead to weight loss and nutrient deficiencies.
  • Dietary restrictions: Women who follow specific diets, including vegans and those with food intolerances and allergies, may need to supplement with vitamins and minerals to prevent micronutrient deficiencies.
  • Nutrient deficiencies: Some people may need a supplement after a blood test reveals a deficiency in a vitamin or mineral. Correcting deficiencies is critical, as a shortage of nutrients like folate has been linked to congenital disabilities.
  • Smoking: Although it’s critical for mothers to avoid cigarettes during pregnancy, those who continue to smoke have an increased need for specific nutrients like vitamin C and folate.
  • Poor nutrition: Women who under-eat or choose low nutrients may need to supplement vitamins and minerals to avoid deficiencies.
  • Multiple pregnancies: Women carrying more than one baby have higher micronutrient needs than women carrying one baby. Supplementing is often necessary to ensure optimal nutrition for both the mother and her babies.
  • Genetic mutations like MTHFR: Methylenetetrahydrofolate reductase (MTHFR) is a gene that converts folate into a form that the body can use. Pregnant women with this gene mutation may need to supplement with a specific form of folate to avoid complications.

In addition, experts like those at the American College of Obstetricians and
Gynecologists (ACOG)
suggest that all pregnant people take a prenatal vitamin and folic acid supplements. This is advised to fill nutritional gaps and prevent developmental abnormalities at birth like spina bifida.

Depending on your personal circumstances, be prepared to take on the task of adding supplements to your daily routine if directed by your healthcare provider.

Herbal supplements can help with ailments — with caution

In addition to micronutrients, herbal supplements are popular.

One 2019 study found that 15.4 per cent of pregnant women in the United States use herbal supplements. However, not all disclose to their physicians they’re taking them. (A 2017 study discovered that about 25 per cent of herbal supplement users in the United States don’t tell their doctors.)

While some herbal supplements may be safe to take during pregnancy, there are far more that might not be.

Although some herbs can help with common pregnancy ailments like nausea and upset stomach, some may harm both you and the baby.

Unfortunately, there isn’t much research regarding the use of herbal supplements by pregnant people, and much is unknown about how the supplements can affect you.

The safest bet? Keep your doctor in the know about any changes to your eating plan and supplements.

Just as with medications, your doctor should approve and supervise all micronutrient and herbal supplements to ensure that they’re necessary and taken in safe amounts.

Always purchase vitamins from a reputable brand with its products evaluated by third-party organizations like the United States Pharmacopeia (USP).

This ensures that the vitamins adhere to specific standards and are commonly safe to take. Not sure which brands are reputable? Your local pharmacist can be a lot of help.

1. Folate

Folate is a B vitamin that plays an integral role in DNA synthesis, red blood cell production, and fetal growth and development.

Folic acid is the synthetic form of folate found in many supplements. It gets converted into the active form of folate — L-methyl folate — in the body.

It’s recommended to take at least 600 micrograms (mcg) of folate or folic acid per day to reduce the risk of neural tube defects and congenital abnormalities like cleft palate and heart defects.

A review of five randomized studies, including 6,105 women, supplementing with folic acid daily was connected with a decreased risk of neural tube defects. No negative side effects were noted.

Although adequate folate can be obtained through diet, many women don’t eat enough folate-rich foods, making supplementation necessary.

Additionally, the Centers for Disease Control and Prevention (CDC) suggests that all women of childbearing age consume at least 400 mcg of folate or folic acid per day.

This is because many pregnancies are unplanned, and birth abnormalities due to a folate deficiency can occur very early in pregnancy, even before most women know they’re pregnant.

It may be wise for pregnant women, especially those with an MTHFR genetic mutation, to choose a supplement that contains L-methyl folate to ensure maximum uptake.

2. Prenatal vitamins

Prenatal vitamins are multivitamins that are specially formulated to meet the increased demand for micronutrients during pregnancy.

They’re intended to be taken before conception and during pregnancy and breastfeeding.

Observational studies have revealed that supplementing with prenatal vitamins decreases the risk of preterm birth and preeclampsia. Preeclampsia is a potentially dangerous complication characterized by high blood pressure and possibly protein in the urine.

While prenatal vitamins aren’t meant to replace your healthy eating plan, they may help prevent nutritional gaps by providing extra micronutrients in high demand during pregnancy.

Since prenatal vitamins contain the vitamins and minerals you’ll need, additional vitamin or mineral supplements may not be necessary unless your doctor suggests.

Doctors and available over-the-counter often prescribe prenatal vitamins.

3. Iron

The need for iron increases significantly during pregnancy as maternal blood volume increases by about 45 per cent.

Iron is critical for oxygen transport and the healthy growth and development of your baby and the placenta.

In the United States, the prevalence of iron deficiency in pregnant women is around 18 per cent, and 5 per cent of these women have anemia.

Anemia during pregnancy has been associated with preterm delivery, maternal depression, and infant anemia.

The recommended intake of 27 milligrams (mg) of iron per day can be met through most prenatal vitamins. However, if you have iron deficiency or anemia, you’ll need higher doses of iron, managed by your doctor.

If you aren’t iron deficient, you shouldn’t take more than the suggested iron intake to avoid adverse side effects. These may include constipation, vomiting, and abnormally high hemoglobin levels.

4. Vitamin D

This fat-soluble vitamin is important for immune function, bone health, and cell division.

Vitamin D deficiency during pregnancy has been linked to an increased risk of cesarean section, preeclampsia, preterm birth, and gestational diabetes.

The current recommended intake of vitamin D during pregnancy is 600 IU or 15 mcg per day. However, some experts suggest that vitamin D needs during pregnancy are much higher.

Check-in with your doctor regarding screening for vitamin D deficiency and proper supplementation.

5. Magnesium

Magnesium is a mineral involved in hundreds of chemical reactions in your body. It plays a critical role in immune, muscle, and nerve function.

Deficiency in this mineral during pregnancy may increase the risk of chronic hypertension and premature labour.

Some studies suggest that supplementing with magnesium may reduce the risk of complications like fetal growth restriction and preterm birth.

6. Ginger

Ginger root is generally used as a spice and herbal supplement.

In supplement form, you may have heard of it used to treat nausea caused by motion sickness, pregnancy, or chemotherapy.

A review of four studies suggested that ginger is safe and effective for treating pregnancy-induced nausea and vomiting.

Nausea and vomiting are common during pregnancy, with up to 80 per cent of women experiencing them in the first trimester of pregnancy.

Though ginger may help reduce this unpleasant pregnancy complication, more research is needed to identify the maximum safe dosage. Double-check with your doctor to see if you need it.

7. Fish oil

Fish oil contains docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), two essential fatty acids important for a baby’s brain development.

Supplementing with DHA and EPA in pregnancy might boost post-pregnancy brain development in your baby and decrease maternal depression, though research on this topic isn’t conclusive.

Although observational studies have shown improved cognitive function in the children of women who supplemented with fish oil during pregnancy, several controlled studies have failed to show a consistent benefit.

For example, one 2010 study involving 2,399 women found no difference in the cognitive function of infants whose mothers had supplemented with fish oil capsules containing 800 mg of DHA per day during pregnancy compared with infants whose mothers did not.

This study also found that supplementing with fish oil did not affect maternal depression.

However, the study did find that supplementing with fish oil protected against preterm delivery, and some evidence suggests that fish oil may benefit fetal eye development.

Maternal DHA levels are important for proper fetal development, and supplementing is considered safe. The jury is still out on whether taking fish oil during pregnancy is necessary.

To get DHA and EPA through food, it’s encouraged to consume two to three servings of low-mercury fish like salmon, sardines, or pollock per week.

8. Probiotics

Given increased general awareness of gut health, many parents-to-be turn to probiotics.

Probiotics are living microorganisms that are thought to benefit digestive health.

Many studies have shown that probiotics are safe to take during pregnancy, and no harmful side effects have been identified, aside from a shallow risk of probiotic-induced infection.

Several studies have shown that supplementing with probiotics may reduce the risk of gestational diabetes, postpartum depression, and infant eczema and dermatitis.

Research on probiotic use in pregnancy is ongoing, and more about the role of probiotics in maternal and fetal health is sure to be discovered.

9. Choline

Choline plays a vital role in a baby’s brain development and helps prevent abnormalities of the brain and spine.

The current recommended daily allowance of choline during pregnancy (450 mg per day) has been thought to be inadequate and that an intake closer to 930 mg per day is optimal instead.

Note that prenatal vitamins often don’t contain choline. Your doctor may recommend a separate choline supplement.