Prenatal Vitamins: What You Need to Know

Taking prenatal vitamins is one of the simplest, most important things you can do for your baby's development—ideally starting before you even conceive. While a healthy diet is the foundation of prenatal nutrition, vitamins fill in nutritional gaps that even the best eating habits might miss.

But walking down the supplement aisle can be overwhelming. Gummies or pills? Prescription or over-the-counter? Which nutrients actually matter? Let's break down what you need to know about choosing and taking prenatal vitamins.

Why Prenatal Vitamins Matter ACOG

Your nutritional needs increase significantly during pregnancy, and certain nutrients are critical for your baby's development.

The reality of pregnancy nutrition:

• Calorie needs only increase by about 300/day in 2nd and 3rd trimester
• But nutrient needs increase by 25-50% for many vitamins and minerals
• It's nearly impossible to get everything from food alone
• Some nutrients are crucial in early pregnancy—before you know you're pregnant

Why "regular" multivitamins aren't enough:

• Don't contain enough folic acid
• May have unsafe levels of vitamin A
• Often missing key pregnancy nutrients
• Not formulated for pregnancy's unique demands

When to Start Taking Prenatal Vitamins ACOG

The answer might surprise you.

Ideally: Before conception

• Neural tube develops in first 28 days—often before you know you're pregnant
• Folic acid needs to be in your system BEFORE conception
• Start when you begin trying to conceive
• Or as soon as you stop using birth control

At minimum: As soon as you know you're pregnant

• Better late than never
• Start immediately upon positive test
• Continue throughout pregnancy
• Most doctors recommend continuing while breastfeeding

If pregnancy is unplanned:

• Start immediately
• Don't panic about weeks you missed
• Your body has some nutrient stores
• Talk to your provider about your specific situation

The Essential Nutrients ACOG

Not all prenatal vitamins are created equal. Here's what to look for.

Folic Acid (400-800 mcg minimum)

• Prevents neural tube defects (spina bifida, anencephaly)
• Critical in first trimester
• Some women need higher doses (ask your provider)
• Folate is the food form; folic acid is the supplement form

Iron (27 mg)

• Blood volume increases 50% during pregnancy
• Prevents anemia
• Supports placenta development
• Supports baby's blood supply

Calcium (200-300 mg, with rest from diet)

• Builds baby's bones and teeth
• Protects your bone density
• Supports heart, muscle, and nerve function
• Need 1000 mg total daily

Vitamin D (600 IU minimum)

• Works with calcium for bone health
• Supports immune function
• Many women are deficient
• Some experts recommend 1000-2000 IU

DHA/Omega-3 (200-300 mg)

• Crucial for brain and eye development
• Often in separate supplement
• Can come from fish oil or algae (vegetarian)
• Not always included in prenatal vitamins

Iodine (150 mcg)

• Essential for thyroid function
• Crucial for baby's brain development
• Not in all prenatal vitamins—check the label
• Important throughout pregnancy and breastfeeding

Choosing a Prenatal Vitamin ACOG

With hundreds of options, here's how to choose.

Over-the-counter vs. prescription:

• Most OTC prenatals are perfectly adequate
• Prescription may be needed for specific deficiencies
• Prescription may be covered by insurance
• Ask your provider if they recommend a specific brand

Pills, gummies, or liquids:

• Pills: Most complete nutrition, but harder for some to swallow
• Gummies: Easier to take, but often missing iron and calcium
• Liquids: Good for those who can't swallow pills
• Choose what you'll actually take consistently

What to look for on the label:

• At least 400 mcg folic acid
• 27 mg iron (unless you're taking a gummy)
• 150 mcg iodine
• 600 IU vitamin D
• Third-party testing (USP, NSF, or ConsumerLab seal)

What to avoid:

• More than 10,000 IU vitamin A (can cause birth defects)
• Herbal additives unless approved by your provider
• Products without third-party verification
• "Mega-dose" vitamins

Managing Side Effects ACOG

Prenatal vitamins can cause some unpleasant effects, but there are solutions.

Nausea:

• Take with food, not on empty stomach
• Take at night before bed
• Try a different brand
• Gummies may be easier on stomach
• Ask about splitting the dose

Constipation (usually from iron):

• Increase fiber and water intake
• Take a gentle stool softener
• Try a slow-release iron formula
• Ask provider about taking every other day if severe

Can't swallow large pills:

• Try gummies (but add iron supplement if needed)
• Look for smaller pills or capsules
• Try liquid formulas
• Some pills can be split (check with pharmacist)

Fishy taste/burps from DHA:

• Take at night
• Freeze the capsules
• Look for enteric-coated versions
• Try algae-based DHA instead of fish oil

Special Situations ACOG

Some women have additional considerations.

History of neural tube defects:

• May need 4,000 mcg (4 mg) folic acid
• Prescription dose required
• Start at least 1 month before conception
• Talk to your provider

Twins or multiples:

• May need additional supplementation
• Iron needs often higher
• Follow your provider's specific recommendations
• More frequent monitoring of nutrient levels

Previous bariatric surgery:

• Absorption may be impaired
• May need different forms of vitamins
• Additional supplementation often needed
• Close monitoring essential

Vegetarian or vegan:

• Ensure adequate B12
• May need additional iron
• DHA from algae rather than fish
• Consider additional calcium if avoiding dairy

Anemia:

• May need additional iron beyond prenatal
• Take iron with vitamin C for better absorption
• Avoid taking with calcium (inhibits absorption)
• Follow provider recommendations

What About Food Sources? ACOG

Vitamins supplement a healthy diet—they don't replace it.

Folate-rich foods:

• Leafy greens (spinach, kale)
• Fortified cereals and breads
• Beans and lentils
• Citrus fruits

Iron-rich foods:

• Lean red meat
• Poultry and fish
• Beans and legumes
• Fortified cereals

Calcium-rich foods:

• Dairy products
• Fortified plant milks
• Leafy greens
• Fortified orange juice

DHA-rich foods:

• Fatty fish (salmon, sardines)—limit to 2-3 servings/week
• DHA-fortified eggs
• Walnuts and flaxseed (provide ALA, which converts to DHA)

Common Questions ACOG

Can I take regular vitamins if I run out of prenatals?
Don't make it a habit, but a day or two won't hurt. The main concern is vitamin A levels—check that regular multivitamins don't exceed safe amounts.

What if I forget to take my vitamin?
Take it when you remember. If it's almost time for your next dose, just take one—don't double up.

Are expensive brands better?
Not necessarily. Many generic store brands contain the same nutrients. Look at the label, not the price.

Do I need to continue after birth?
Most providers recommend continuing while breastfeeding. Your nutrient needs remain elevated during lactation.

The Bottom Line

Prenatal vitamins are a simple but crucial part of a healthy pregnancy. Start them before conception if possible, choose a reputable brand with the key nutrients, and take them consistently throughout pregnancy and breastfeeding. ACOG

Remember:

• Start before conception if possible
• Look for folic acid, iron, calcium, vitamin D, DHA, and iodine
• Choose what you'll actually take consistently
• Food comes first, but vitamins fill the gaps
• Talk to your provider about your specific needs

Clara is here when you have questions about prenatal nutrition or choosing the right vitamins.