When should I start taking prenatal vitamins?

Ideally, start at least 1 month before trying to conceive. Neural tube closure occurs just 26–28 days after fertilisation — often before a pregnancy test is positive. Starting early ensures adequate folate and other nutrients are present during this critical window. If your pregnancy was unplanned, start as soon as you find out.

Is it safe to eat fish during pregnancy?

Yes — and it is encouraged. The FDA recommends 8–12 oz of low-mercury seafood per week. Fatty fish like salmon, sardines, and trout are excellent sources of DHA (critical for fetal brain development), protein, vitamin D, and iodine. The fish to avoid are high-mercury species: shark, swordfish, king mackerel, bigeye tuna, orange roughy, and tilefish.

How much water should I drink during pregnancy?

The ACOG recommends approximately 8–10 cups (64–80 oz / ~2 litres) of fluid per day during pregnancy, from all sources including food. Needs increase in hot weather, with exercise, and in the third trimester. Adequate hydration supports increased blood volume, amniotic fluid maintenance, nutrient transport, and can reduce the risk of urinary tract infections and preterm contractions.

🥦 Based on ACOG · NIH · CDC · FDA Guidelines

Prenatal Nutrition Guide

What to eat, what to avoid, and why — covering all 12 key nutrients across all 40 weeks, with trimester-specific guidance backed by clinical evidence.

Extra Calorie Needs by Trimester

IOM / Dietary Reference Intakes — for a healthy pre-pregnancy weight

🌱

1st Trimester

Weeks 1–13

+0 calories

No additional calories are needed. The embryo is very small; its metabolic demands are minimal. Focus on nutrient quality, not quantity — this is when folic acid and B vitamins are most critical.

🌸

2nd Trimester

Weeks 14–26

+340 calories/day

Fetal growth accelerates and energy needs increase. 340 extra calories is roughly a small snack — a banana with peanut butter, or Greek yogurt with berries. Focus on protein, iron, and calcium.

🌟

3rd Trimester

Weeks 27–40

+450 calories/day

Fetal weight gain peaks — the baby gains roughly half its birth weight in the last 10 weeks. DHA needs are highest now. Smaller, more frequent meals help manage heartburn as the uterus compresses the stomach.

Key Nutrients During Pregnancy

Tap any nutrient card to see food sources, dosing details, and clinical tips

What Your Prenatal Vitamin Covers

Most prenatal vitamins have significant gaps — always read the label

Covered— in most brands

Partial— underdosed or variable

Gap— missing from most

Folic Acid

Present in virtually all prenatal vitamins at ≥400 mcg

Iron

Typically 27 mg — matches pregnancy RDA

Vitamin B12

Usually present at adequate levels

Vitamin C

Usually present at adequate levels

Zinc

Usually present, though amounts vary

Vitamin D

Often only 400 IU; many experts recommend 600–1,000 IU — check label

Calcium

Typically only 150–200 mg — far below the 1,000 mg/day target; supplement separately

Magnesium

Often absent or low dose; diet must fill the gap

Iodine

Missing from many brands; AAP recommends 150 mcg in prenatal supplement — check label

DHA (Omega-3)

Not in most standard prenatals; look for brands with added DHA or take separately

Choline

Almost universally absent; only 8.5% of pregnant women meet the 450 mg target through diet — separate supplement often needed

Practical checklist for choosing a prenatal vitamin: Look for at least 400 mcg folate (methylfolate is better absorbed than folic acid for some women), 27 mg iron, 150 mcg iodine, 600 IU vitamin D, and ideally 200–300 mg DHA. Consider adding a separate choline supplement (bitartrate form).

Foods to Avoid During Pregnancy

Based on CDC and FDA food safety guidance for pregnant women

About This Guide

Nutrition during pregnancy directly influences fetal development, pregnancy outcomes, and the long-term health of your child. This guide covers the 12 most important nutrients for pregnancy, based on current Dietary Reference Intakes (DRI) from the Institute of Medicine and clinical guidance from ACOG, the NIH Office of Dietary Supplements, and the CDC.

Every pregnancy is different. Women with specific health conditions, dietary restrictions, or multiple pregnancies may have different needs. The values here represent general population guidelines — your healthcare provider is the right person to advise on your individual situation.

Looking for more tools? Use our EDD calculator to find your due date, our weight gain calculator for personalised gain targets, or our week-by-week guide to follow your baby's development.

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Prenatal Nutrition — FAQs

Answers to common questions

Yes — even with a nutrient-rich diet, it is extremely difficult to meet all pregnancy-specific requirements through food alone. Folic acid (needed from before conception), iron, iodine, and vitamin D are the most common shortfalls. A prenatal vitamin covers the foundational gaps, but it does not replace a healthy diet, and important nutrients like choline, DHA, and calcium are often absent or underdosed in most prenatal formulas.

Three nutrients are the most common gaps: (1) Choline — absent from most prenatals, yet critical for fetal brain development; only 8.5% of pregnant women meet the 450 mg/day target. (2) DHA — not in most standard prenatals; look for brands that include DHA or take a separate fish-oil or algae-based supplement. (3) Iodine — many brands contain none, despite the AAP recommending 150 mcg/day in prenatal supplements. Always read your prenatal vitamin's label.

Standard adult multivitamins are not formulated for pregnancy. They typically contain lower doses of folate and iron, may have the wrong form of nutrients (e.g. vitamin A as retinol rather than beta-carotene — excess retinol is teratogenic), and lack the pregnancy-specific nutrient profile. Use a prenatal vitamin labelled specifically for pregnancy, and verify it contains at least 400 mcg folate, 27 mg iron, 150 mcg iodine, and ideally DHA.

References & Sources

NIH Office of Dietary Supplements — Dietary Supplements and Pregnancy — Health Professional Fact Sheet (2024)
ACOG — Healthy Eating During Pregnancy — FAQs (2023)
CDC — Folic Acid — Recommendations (2024)
FDA — Advice About Eating Fish for Those Who Are Pregnant (2024)
CDC — Food Safety for Pregnant Women (2024)
Institute of Medicine (IOM) — Dietary Reference Intakes for Energy — Caloric Needs in Pregnancy (2005 (foundational))
PMC / Nutrition Reviews — Nutrition Recommendations in Pregnancy and Lactation (PMC5104202) (2017)
PMC / Nutrients — Choline Supplementation in Pregnancy: Current Evidence and Implications (PMC10709661) (2023)
American Journal of Obstetrics & Gynecology MFM — Omega-3 Fatty Acid Supplementation During Pregnancy (2024)
American Academy of Pediatrics (AAP) & American Thyroid Association — Iodine Deficiency, Pollutant Chemicals, and the Thyroid: New Information on an Old Problem (2014 (foundational AAP iodine guidance))
Adebiyi et al. — British Journal of Nutrition — Papaya (Carica papaya) consumption is unsafe in pregnancy: fact or fable? (PMID 12144723) (2002)
Räikkönen et al. — American Journal of Epidemiology / PMC7129125 — Maternal licorice consumption during pregnancy and cognitive and psychiatric outcomes in children (systematic review) (2009 / 2020 review)
Iranian Case-Control Study — PMC12327749 — Association between maternal consumption of barberry and congenital anomalies (2024)

This page is for informational purposes only and does not constitute medical advice. All nutrient recommendations are population-level guidelines. Consult your midwife, OB-GYN, or registered dietitian for personalised prenatal nutrition guidance.