Best Prenatal Vitamins: What Should You Be Taking Each Trimester?
Choosing the right prenatal vitamins isn’t just about popping a multivitamin — it’s about making sure your body and baby get what they need, when they need it. In this guide, we break down what your body demands in each trimester and how your supplement strategy should evolve to meet those needs.
Why Prenatal Vitamins Matter
During pregnancy, your body becomes a nutrient delivery system for two. That means your requirements for key vitamins and minerals skyrocket. While a healthy diet forms the base, prenatal vitamins fill the nutritional gaps and help prevent common pregnancy complications, including neural tube defects, anemia, and low birth weight. According to the CDC, folic acid alone can prevent up to 70% of neural tube defects.
Trimester-by-Trimester Vitamin Breakdown
First Trimester: Building Foundations
The first 12 weeks are crucial. Your baby’s neural tube, heart, and brain begin forming. Here’s what your prenatal vitamin must include:
- Folic Acid (400–800 mcg): Prevents neural tube defects. March of Dimes recommends taking folic acid before and during early pregnancy.
- Vitamin B6: Helps manage nausea, a common issue in early pregnancy. Learn more about morning sickness relief.
- Iron (27 mg): Supports increased blood production and reduces anemia risk.
- Vitamin D (600 IU): Essential for bone development and immune health. NIH Fact Sheet.
Second Trimester: Growth Acceleration
From week 13 to 27, your baby is growing fast — and so are their bones and organs. Shift your supplement focus slightly:
- Calcium (1000 mg): If your vitamin doesn’t include this, consider a separate supplement. Supports your baby’s bone development.
- Omega-3 DHA (200–300 mg): Crucial for brain and eye development. See research on DHA during pregnancy.
- Magnesium: Can reduce leg cramps and support muscle function. Check our tips on managing leg cramps.
Pro tip: Some women find it easier to take two smaller doses a day to reduce nausea or constipation from iron.
Third Trimester: Prepping for Birth
The final stretch — weeks 28 to birth — focuses on immune support and prepping your body for labor.
- Iron: Still critical, especially if your iron stores are low. Blood volume is at its highest.
- Vitamin C: Supports iron absorption and immune health.
- Zinc and Iodine: Important for fetal growth and thyroid regulation. Learn more in our third-trimester checklist.
How to Choose a Quality Prenatal Vitamin
Not all prenatal vitamins are created equal. Here’s what to look for:
- Third-party tested: Look for NSF or USP certification for ingredient accuracy and purity.
- No artificial dyes or fillers: Cleaner is better, especially for sensitive stomachs.
- Includes choline and DHA: These are often missing but are vital for brain development.
Can You Get Too Much of a Good Thing?
Yes. Megadosing vitamins — especially A, D, and iron — can be harmful. Always follow your OB-GYN’s guidance and avoid doubling up on multivitamins unless prescribed.
Final Thoughts: Tailor Your Vitamins to Your Trimester
What worked in your first trimester might not be right for your third. Adjusting your prenatal vitamins according to your body’s evolving needs ensures both you and your baby stay on the healthiest path possible.
Pro tip: Keep your doctor informed about any supplements you take — even herbal ones. Personalized care is the best care.
Frequently Asked Questions
Can I start taking prenatal vitamins before getting pregnant?
Yes — in fact, it’s recommended. ACOG suggests taking folic acid at least one month before conception.
What if prenatal vitamins make me nauseous?
Try switching to gummies or take them with a meal at night. Look for formulas with B6 to combat nausea. You can also read our guide to prenatal gummies.
Is it okay to skip days?
Consistency is key. Missing an occasional dose is okay, but aim for daily use to support steady nutrient levels. For tips, check out how to build a vitamin routine.
