Pregnancy is often described as one continuous nutritional journey, but your body's needs don't remain exactly the same throughout those nine months.

Your requirements for several essential nutrients increase once you become pregnant, while your energy needs change more noticeably as pregnancy progresses. At the same time, certain nutrients deserve particular attention during specific stages — for example, folate is especially important before conception and in early pregnancy, while increasing energy needs become more relevant in the second and third trimesters.

Understanding these differences can help you build a more balanced pregnancy diet without getting overwhelmed by constantly changing nutrition advice.

It is important to keep in mind that pregnancy nutrition needs vary depending on your health, diet, pregnancy, medications, and other individual factors. This article provides general nutrition information and is not a substitute for advice from your obstetrician, registered dietitian, or other qualified healthcare professional.

Pregnancy Nutrition at a Glance

Here is a simplified overview of some important changes during pregnancy:

Nutritional consideration	First trimester	Second trimester	Third trimester
Energy (calories)	Generally no additional calories are recommended solely because of pregnancy	About 340 additional kcal/day	About 452 additional kcal/day
Protein	Pregnancy target applies	Pregnancy target applies	Pregnancy target applies
Folate	Particularly important	Pregnancy requirement continues	Pregnancy requirement continues
Iron	Increased pregnancy requirement	Increased pregnancy requirement	Increased pregnancy requirement
Iodine	Increased pregnancy requirement	Increased pregnancy requirement	Increased pregnancy requirement
Choline	Increased pregnancy requirement	Increased pregnancy requirement	Increased pregnancy requirement
Calcium & vitamin D	Pregnancy requirements continue	Pregnancy requirements continue	Pregnancy requirements continue

 

The important point is that not every nutrient has a separate first-, second- and third-trimester target. Many recommended intakes are established as pregnancy-wide targets.

Sources: National Academies' Dietary Reference Intakes; ACOG; NIH Office of Dietary Supplements. [1–7]

First Trimester: Building the Foundations

The first trimester includes some of the earliest and most important developmental processes of pregnancy.

Although calorie requirements generally do not increase solely because of pregnancy during the first trimester, the importance of nutrient quality is already high.

1. Folate deserves particular attention

Folate is particularly important around conception and during early pregnancy because it is involved in cell division and DNA synthesis.

The National Academies' recommended dietary allowance for folate during pregnancy is 600 micrograms of dietary folate equivalents (mcg DFE) per day, compared with 400 mcg DFE per day for non-pregnant women aged 19–50.

The importance of folic acid begins even before pregnancy. Neural tube development occurs very early in pregnancy, often before someone knows they are pregnant.

The Centers for Disease Control and Prevention (CDC) recommends that all women capable of becoming pregnant consume 400 mcg of folic acid daily in addition to consuming folate from a varied diet.

Food sources include: leafy green vegetables, legumes, citrus fruits and fortified foods.

Source: CDC; NIH Office of Dietary Supplements; National Academies. [1, 3]

2. Iron needs are higher during pregnancy

Pregnancy increases the body's need for iron. The recommended dietary allowance for iron during pregnancy is 27 mg per day, compared with 18 mg per day for non-pregnant women aged 19–50.

Iron is needed for haemoglobin production and other biological functions, and maternal blood volume increases during pregnancy.

Good dietary sources include meat and seafood, legumes, spinach and iron-fortified foods. Plant sources of iron provide non-heme iron, whose absorption differs from that of heme iron found in animal foods.

If blood tests show iron deficiency or anaemia, your healthcare professional may recommend iron supplementation.

Source: NIH Office of Dietary Supplements — Iron; National Academies. [2]

3. Don't focus only on calories

Morning sickness, nausea, food aversions and changes in appetite can make eating differently during the first trimester.

Because additional calories are generally not required solely because of pregnancy during the first trimester, the focus is usually on maintaining adequate nutrition and hydration rather than "eating for two."

If severe nausea or vomiting makes it difficult to keep food or fluids down, speak with your healthcare professional.

Second Trimester: Energy and Nutrient Needs Increase

As pregnancy progresses, your baby's growth and your body's physiological changes increase your nutritional demands.

This is when additional energy requirements become more significant.

1. Calorie requirements increase

According to the National Academies' pregnancy energy recommendations, average additional energy needs are approximately:

• First trimester: no additional calories
• Second trimester: +340 kcal/day
• Third trimester: +452 kcal/day

These are population-level estimates, not personalised calorie prescriptions. Your actual needs can vary depending on your pre-pregnancy weight, activity level, age, pregnancy and other factors.

ACOG similarly emphasises that pregnancy is not a time to follow a restrictive diet or to interpret "eating for two" literally.

Sources: National Academies; ACOG. [1, 8]

2. Protein becomes increasingly important

Protein is required for the growth and maintenance of maternal and fetal tissues.

The National Academies' recommended dietary allowance for protein during pregnancy is 71 g per day for women aged 19–50.

Rather than focusing on protein as a single supplement or food, it can be distributed throughout the day through foods such as:

• Pulses and legumes
• Dairy products
• Eggs
• Nuts and seeds
• Soy foods
• Fish, poultry and meat, where included in the diet

Individual requirements can differ, particularly for women with specific medical or dietary needs.

Source: National Academies' Dietary Reference Intakes. [1]

3. Iron remains important

The pregnancy recommendation for iron remains 27 mg/day throughout pregnancy.

The second trimester is therefore not a point at which iron suddenly becomes necessary; rather, iron remains an important nutrient throughout pregnancy.

Your healthcare provider may monitor haemoglobin and iron status during pregnancy and recommend supplementation when appropriate.

Source: NIH Office of Dietary Supplements; ACOG. [2, 9]

Third Trimester: Supporting Rapid Growth and Preparing for Birth

The third trimester brings another increase in energy needs, while the pregnancy-wide requirements for many essential nutrients continue.

1. Energy needs are highest

The National Academies estimate an average additional energy requirement of approximately 452 kcal per day during the third trimester.

This does not mean that every pregnant woman should add exactly 452 calories to her diet. Individual energy requirements depend on several factors.

The quality of those additional calories matters too. Nutrient-dense foods can help provide energy alongside protein, vitamins and minerals.

Source: National Academies; ACOG. [1, 8]

2. Continue prioritising protein-rich foods

Protein needs remain important during the third trimester as fetal and maternal tissues continue to develop.

Rather than relying on one particular food, aim for a variety of protein sources across meals and snacks.

For vegetarian diets, useful sources can include:

• Dal and other pulses
• Beans and chickpeas
• Soy foods
• Milk and yoghurt
• Paneer
• Eggs, if included
• Nuts and seeds

Women following restrictive diets may benefit from individual dietary assessment by a qualified professional.

Source: National Academies; ACOG. [1, 8]

3. Calcium and vitamin D continue to matter

Calcium is important for bone development and other physiological functions, while vitamin D is involved in calcium absorption and bone health.

For pregnant women aged 19–50, the National Academies' recommended dietary allowance for calcium is 1,000 mg/day.

The recommended dietary allowance for vitamin D during pregnancy is 600 IU (15 mcg) per day.

These targets do not increase specifically in the third trimester; they apply across pregnancy.

Sources: NIH Office of Dietary Supplements — Calcium and Vitamin D; National Academies. [5, 6]

Nutrients That Matter Throughout Pregnancy

Some of the most important pregnancy nutrients shouldn't be thought of as "first trimester" or "third trimester" nutrients. Their importance extends throughout pregnancy.

Folate

Pregnancy RDA: 600 mcg DFE/day

Folate is required for DNA synthesis and cell division. Adequate folic acid intake before and during early pregnancy is particularly important in relation to neural tube development.

Sources: CDC; NIH ODS; National Academies. [1, 3]

Iron

Pregnancy RDA: 27 mg/day

Iron requirements increase during pregnancy, partly because of increased maternal blood production and the needs of the developing fetus and placenta.

Sources: NIH ODS; National Academies. [1, 2]

Iodine

Pregnancy RDA: 220 mcg/day

Iodine is required for thyroid hormone production. Thyroid hormones play an important role in normal growth and development.

Sources of iodine include iodised salt, dairy products, seafood and some other foods, although the amount can vary considerably.

Source: NIH Office of Dietary Supplements — Iodine. [4]

Choline

Pregnancy AI: 450 mg/day

Choline is an essential nutrient involved in cell structure, neurotransmitter production and other physiological processes.

Food sources include eggs, meat, fish, dairy products, soybeans and some legumes and vegetables.

Source: NIH Office of Dietary Supplements — Choline; National Academies. [7]

Calcium

Pregnancy RDA for women aged 19–50: 1,000 mg/day

Calcium is important for bones and teeth as well as normal muscle and nerve function.

Milk, yoghurt, cheese and calcium-fortified foods can provide calcium. Some plant foods also contribute calcium.

Source: NIH Office of Dietary Supplements — Calcium. [5]

Vitamin D

Pregnancy RDA: 600 IU (15 mcg)/day

Vitamin D contributes to calcium absorption and bone health and has other physiological roles.

Sources include fortified foods, some fish and exposure to sunlight, although vitamin D status and sun exposure vary considerably between individuals.

Source: NIH Office of Dietary Supplements — Vitamin D. [6]

What About Omega-3 Fatty Acids During Pregnancy?

Fish can be an important source of nutrients during pregnancy, including omega-3 fatty acids.

The U.S. Food and Drug Administration (FDA) and Environmental Protection Agency (EPA) recommend that people who are pregnant or breastfeeding eat 8–12 ounces (2–3 servings) per week of fish from choices lower in mercury.

Fish choices should be made carefully because mercury exposure can be harmful to the developing nervous system.

For people who do not eat fish, whether an omega-3 supplement is appropriate is an individual decision that can be discussed with a healthcare professional.

Source: FDA & EPA — Advice About Eating Fish for Those Who Are Pregnant or Breastfeeding. [10]

Does Your Diet Need to Change Every Trimester?

Not necessarily.

One of the biggest misconceptions about pregnancy nutrition is that you need a completely different diet every few months.

A better way to think about it is:

First trimester

Focus: Nutrient quality, folate, iron and managing nausea/food aversions while maintaining adequate food and fluid intake.

Second trimester

Focus: Increasing energy needs, continued attention to protein, iron, folate and overall dietary variety.

Third trimester

Focus: Further increased energy needs, continued protein and micronutrient adequacy, hydration and maintaining a varied, nutrient-dense diet.

Across all three trimesters, the foundation remains similar: a varied diet that provides adequate energy, protein, vitamins, minerals and fluids, adapted to your individual needs.

Pregnancy Nutrition Is Not One-Size-Fits-All

Nutritional requirements can be affected by factors including:

• Pre-pregnancy nutritional status
• Vegetarian or vegan diets
• Food allergies and intolerances
• Anaemia or other nutrient deficiencies
• Diabetes or gestational diabetes
• Thyroid conditions
• Multiple pregnancy
• Medications and supplements
• Weight gain during pregnancy
• Nausea and vomiting
• Other medical conditions

This is why prenatal supplements and dietary recommendations should not be treated as interchangeable between women.

Your obstetrician, registered dietitian, or other qualified healthcare professional can help determine whether you need additional supplementation or dietary adjustments.

The Bottom Line

Pregnancy nutrition isn't about eating more from the moment you see a positive pregnancy test. It is about meeting changing nutritional needs while maintaining a varied and balanced diet.

In the first trimester, nutrient quality and folate are particularly important, while additional calories are generally not required solely because of pregnancy.

In the second trimester, energy requirements increase and maintaining adequate protein, iron and overall nutrient intake becomes increasingly important.

In the third trimester, energy requirements increase further while the need for a nutrient-dense, varied diet continues.

And throughout pregnancy, nutrients such as folate, iron, iodine, choline, calcium and vitamin D remain important.

Rather than trying to build the "perfect pregnancy diet," focus on consistent nourishment and seek personalised advice when your individual circumstances require it.

Sources & Further Reading

1. National Academies of Sciences, Engineering, and Medicine — Dietary Reference Intakes
Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids.
https://nap.nationalacademies.org/catalog/10490/dietary-reference-intakes-for-energy-carbohydrate-fiber-fat-fatty-acids

2. National Institutes of Health, Office of Dietary Supplements — Iron
https://ods.od.nih.gov/factsheets/Iron-HealthProfessional/

3. National Institutes of Health, Office of Dietary Supplements — Folate
https://ods.od.nih.gov/factsheets/Folate-HealthProfessional/

4. National Institutes of Health, Office of Dietary Supplements — Iodine
https://ods.od.nih.gov/factsheets/Iodine-HealthProfessional/

5. National Institutes of Health, Office of Dietary Supplements — Calcium
https://ods.od.nih.gov/factsheets/Calcium-HealthProfessional/

6. National Institutes of Health, Office of Dietary Supplements — Vitamin D
https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional/

7. National Institutes of Health, Office of Dietary Supplements — Choline
https://ods.od.nih.gov/factsheets/Choline-HealthProfessional/

8. American College of Obstetricians and Gynecologists (ACOG) — Nutrition During Pregnancy
https://www.acog.org/womens-health/faqs/nutrition-during-pregnancy

9. American College of Obstetricians and Gynecologists — Anemia in Pregnancy
https://www.acog.org/womens-health/faqs/anemia-and-pregnancy

10. U.S. Food and Drug Administration & U.S. Environmental Protection Agency — Advice About Eating Fish for Those Who Are Pregnant or Breastfeeding
https://www.fda.gov/food/consumers/advice-about-eating-fish

Medical Disclaimer

This article is intended for general educational purposes and does not constitute medical or nutritional advice. Pregnancy nutrition requirements vary between individuals. Speak with your obstetrician, registered dietitian, or other qualified healthcare professional before making significant dietary changes or starting, stopping, or changing supplements during pregnancy.