Our understanding of nutrition during pregnancy has undergone a significant transformation. The outdated saying “eating for two,” which focused mainly on quantity and increased caloric intake, has been replaced by a more sophisticated approach: “nourishing for two.” This modern view emphasizes the quality and nutrient density of the diet, as pregnancy is a period of unique physiological changes that creates a critical window of opportunity to influence the long-term health of both the mother and the child.
A well-balanced diet and targeted supplementation not only support the optimal growth and development of the fetus but can also significantly reduce the risk of pregnancy-related complications such as gestational diabetes, anemia, preeclampsia, or preterm birth. A woman’s nutritional status forms the foundation for the baby’s healthy development and the overall well-being of both mother and child.
What will you learn in this article?
- The most common nutritional deficiencies in pregnant women
- Trimester guide: how nutritional needs evolve during pregnancy
- Supplementation before conception vs. during pregnancy
- Key takeaways
The most common nutritional deficiencies in pregnant women
In the European population, despite the relative abundance of food, pregnant women face specific risks of deficiencies in key micronutrients. These deficiencies are caused by both the increased demands of the pregnant body and modern dietary habits, as well as the difficulty of covering all necessary nutrients in optimal amounts through diet alone.
Folic acid (also known as folate or vitamin B9)
Folic acid, or its natural form folate, is an essential vitamin for DNA synthesis, proper cell division, and red blood cell formation. Its role is especially critical during the first weeks of pregnancy, when organogenesis and the formation of the neural tube—which later develops into the baby’s brain and spinal cord—take place.
The critical window for neural tube closure occurs around day 28 after conception, a time when many women do not yet know they are pregnant. This is the main reason why health organizations, including the World Health Organization (WHO), recommend universal folic acid supplementation at a dose of 400–800 µg daily for all women planning to conceive, ideally starting three months before conception. During pregnancy, the recommended daily dose increases to 600–1000 µg. Although folate is found in many foods—especially dark leafy greens, liver, and legumes—it is very difficult to achieve a protective dose through food alone. Folate is highly unstable and breaks down easily with heat, light, and storage, significantly reducing its content in commonly consumed foods. For this reason, folate supplementation is essential for women planning a pregnancy.
It is important to distinguish between different forms of this vitamin in supplements. Many products contain synthetic folic acid, which must first be converted in the body into its biologically active form, methylfolate. It is estimated that up to 40–60% of the European population has a genetic variant of the MTHFR enzyme that hinders this conversion. In such women, synthetic folic acid may accumulate without being properly utilized. Therefore, supplementing with the active methylfolate form ensures bioavailability for all women, regardless of their genetic profile. That’s why we enriched Pregnancy Essentials with 400 mcg of the patented bioactive folate form Quatrefolic®, which provides pregnant women with the necessary amount of this key nutrient.
Iron
During pregnancy, major changes occur in the circulatory system. Plasma volume increases by about 50%, while red blood cell volume increases by only 18–30%. This imbalance leads to natural blood dilution, known as physiological anemia of pregnancy. At the same time, the growing fetus and placenta nearly double the daily iron requirement, from approximately 15–18 mg to 27–30 mg per day.
Iron deficiency anemia is the most common nutritional deficiency during pregnancy. It presents in mothers as increased fatigue, shortness of breath, poor concentration, and pallor, and is associated with a higher risk of preterm birth, low birth weight, and increased blood loss during delivery.
Although iron is found in red meat, legumes, and leafy greens, it is often difficult to meet the increased demand through diet alone, especially in the second and third trimesters. In cases of confirmed deficiency, supplementation is appropriate. In the Pregnancy Essentials supplement, iron is provided in a separate capsule to ensure maximum stability and absorption without unwanted interactions. The bisglycinate form of iron has high bioavailability and is gentle on the stomach and digestive tract.
Iodine
Systematic reviews show [1] that iodine intake is insufficient in many European countries, including among women of reproductive age. A significant number of women may already enter pregnancy with an existing deficiency. Iodine is absolutely essential during pregnancy. The fetal thyroid gland does not begin to function independently until around the 20th week of pregnancy. Until then, the fetus is entirely dependent on the mother’s thyroid hormones for proper neurological development.
Even mild iodine deficiency during pregnancy can lead to irreversible cognitive impairment and reduced IQ in the child. It is also associated with a higher risk of miscarriage and low birth weight. The recommended daily intake during pregnancy is around 200–250 µg.
A combination of factors—such as reduced intake of iodized salt and the growing popularity of plant-based diets, which often exclude dairy, eggs, and seafood (natural sources of iodine)—increases the risk of deficiency in pregnant women. Therefore, including iodine in prenatal and pregnancy supplements is a common and recommended practice.
Vitamin D
Vitamin D deficiency is widespread in Europe, especially during winter months and in northern latitudes, due to insufficient sun exposure—the primary natural source of this vitamin.
Vitamin D is essential for the healthy development of bones and teeth and plays a key role in supporting a healthy immune system. Low vitamin D levels during pregnancy are linked to increased risks of gestational diabetes, preeclampsia, preterm birth, and low birth weight in newborns.
Vitamin D works in synergy with vitamin K2—while vitamin D enhances calcium and phosphorus absorption, vitamin K2 directs calcium to where it belongs (bones and teeth) and prevents its deposition in soft tissues and arteries. Together, they support proper mineralization of bones and teeth and contribute to cardiovascular health.
Pregnancy Essentials provides a base dose of 1,000 IU of vitamin D3. Many experts agree that for optimal health, serum levels of vitamin D (i.e., 25(OH)D) should be maintained between 100 and 150 nmol/L. Laboratory tests for vitamin D levels (such as the Vitamin D Level DBS test) can help determine the appropriate dosage needed to achieve optimal health benefits.
Omega-3 Fatty Acids (DHA & EPA)
The importance of omega-3 fatty acids—especially docosahexaenoic acid (DHA)—is traditionally associated with the healthy development of the fetal brain and vision, as DHA is a key structural component of both. In recent years, their role in preventing preterm birth has also come into focus. [2] For the mother, they are important for reducing the risk of depression in late pregnancy and postpartum. [3]
Achieving optimal omega-3 intake through diet alone is difficult for many women. Furthermore, consumption of oily fish—the richest natural sources of omega-3—is often limited due to concerns about heavy metal contamination. Supplementing with a high-quality product is therefore a suitable strategy to prevent deficiency. Krill Oil Plus contains omega-3 fatty acids in phospholipid form, which are more efficiently absorbed and offer high bioavailability. EFSA recommends a daily intake of approximately 350–450 mg of EPA + DHA for pregnant women (with an emphasis on DHA for fetal brain and eye development).
Vitamin B12
Vitamin B12 is essential during pregnancy for the proper development of the baby’s nervous system, the production of red blood cells, and healthy metabolic function. Alongside folate, it plays a key role in cell division and reducing the risk of neural tube defects. Vitamin B12 is found exclusively in animal-based foods, so vegans and vegetarians are at higher risk of deficiency, as are those with absorption disorders. As with folate, it is important to supplement vitamin B12 in its active form. Pregnancy Essentials includes the recommended daily dose of 5 µg of bioactive methylcobalamin, which the body can easily absorb and effectively use.
Calcium and Magnesium: Key Minerals in Pregnancy
Calcium is essential during pregnancy for the development of the baby’s bones and teeth, and for proper muscle and nervous system function. Inadequate calcium intake may lead to the depletion of the mother’s own bone stores, increasing the risk of bone weakening and reduced mineral density. Calcium deficiency is also associated with a higher risk of preeclampsia.
According to EFSA, the recommended daily intake of calcium during pregnancy is approximately 1,000 mg. Calcium absorption naturally increases during pregnancy to help meet the body’s rising demands. In the European population, calcium intake from dairy products is generally sufficient, so widespread supplementation is not always necessary. However, supplementation may be recommended for women with low dietary intake.
Magnesium is an important mineral involved in hundreds of enzymatic processes in the body—from energy production to muscle relaxation and nervous system regulation. During pregnancy, it is essential for preventing muscle cramps and may help alleviate headaches, fatigue, and insomnia. Magnesium also helps reduce the risk of pregnancy-induced hypertension (preeclampsia) and may lower the risk of preterm birth. Given the increased demands of pregnancy, supplementation may be necessary, especially if a woman cannot meet her magnesium needs through diet alone. According to EFSA, the recommended daily intake of magnesium for pregnant women is 300 mg.
Trimester Guide: The Dynamics of Nutritional Needs During Pregnancy
The nutritional needs of a pregnant woman change in line with the dynamic development of the fetus and the physiological adaptations of the mother’s body.
First Trimester (Weeks 1–12): Organ Development
The first trimester is the most crucial and delicate stage in terms of development. During these weeks, all major fetal organ systems—the heart, brain, spine, and limbs—begin to form. The fetus is extremely sensitive at this stage to any negative influences, including medications, alcohol, and nutritional deficiencies or excesses (such as too much vitamin A in the form of retinol).
From a nutritional perspective, quality matters more than quantity. Energy needs do not significantly increase during this period, and the common saying that pregnant women should “eat for two” is a myth—in practice, it is much more important to ensure a sufficient intake of micronutrients that support rapid cell division. Key nutrients in the first trimester include:
-
-
- Folic Acid: essential for neural tube development and cell division.
- Vitamin B12: works with folate to support nervous system development, blood formation, and DNA synthesis.
- Iodine: critical for thyroid hormone production, which is essential for brain development.
- Zinc: contributes to DNA production and protein synthesis, both vital for fetal growth and cell division.
- Vitamin B6: important for the development of the fetal nervous system and can help alleviate pregnancy-related nausea, which affects many women early on.
-
Second Trimester (Weeks 13–26): Accelerated Growth Phase
The second trimester is often referred to as the “golden period” of pregnancy. Morning sickness usually subsides, and women often feel more energetic. The fetus undergoes a phase of rapid growth, with skeletal and muscular development, and the mother begins to feel fetal movements.
During this phase, energy and nutrient requirements increase:
-
-
- Calories: energy needs rise by approximately 300–350 kcal per day—roughly equivalent to a larger snack (e.g., yogurt with fruit and nuts).
- Protein: requirements increase to around 1.1–1.3 g per kg of body weight, supporting the development of fetal tissues, the placenta, and the uterus.
-
Micronutrients: Structural nutrients become particularly important:
- Iron: needed due to the significant increase in maternal blood volume.
- Calcium: essential for mineralizing the rapidly developing fetal skeleton.
- Magnesium: supports muscle and nerve function, helps prevent cramps.
- Vitamin D: works with vitamin K2 to promote calcium deposition in bones and healthy skeletal development.
- Vitamin C: important for collagen formation, which intensifies during this period.
- Omega-3 (DHA): supplementation should begin no later than week 20 to reduce the risk of preterm birth.
-
Third Trimester (Weeks 27–40): Peak Demand and Nutrient Storage
In the third trimester, fetal growth reaches its peak. The baby gains weight, organs (especially the lungs) mature, and the brain undergoes its most intense developmental phase. The fetus also builds its own stores of key nutrients like iron and calcium. For the mother, this is the most physically demanding stage. The expanding uterus puts pressure on the stomach and other organs, making it difficult to eat large meals and increasing heartburn. Nutrient demands are at their highest:
-
-
- Calories: energy needs increase by up to 450 kcal per day compared to pre-pregnancy levels.
- Protein: daily needs rise to 1.3–1.5 g per kg of body weight.
-
Key Nutrients:
- Iron: requirements peak due to fetal growth and increased blood volume; the fetus builds its own iron stores. The mother’s risk of anemia is highest in this trimester.
- Omega-3 (EPA + DHA): crucial for the final development of the brain, eyes, and nervous system, and for reducing the risk of postpartum depression.
-
Calcium and Vitamin D: essential for the final stage of skeletal mineralization.
-
Magnesium: helps prevent muscle cramps and may reduce the risk of premature uterine contractions.
-
Probiotics: support digestion, immunity, and reduce the risk of pregnancy-related constipation. Also important for preventing atopic eczema and allergies in children.
-
Supplementation Before Conception vs. During Pregnancy
Although supplementation for women planning pregnancy may seem similar to that during pregnancy, the strategy differs. Before conception, the main goal is prevention and proactive preparation – building up stores of key nutrients to reduce the risk of birth defects and help the body enter pregnancy without deficiencies. This is based on the fact that the most sensitive stages of embryonic development occur in the first weeks after conception, often before a woman knows she's pregnant. Once pregnancy is confirmed, the supplementation strategy shifts from preventive to supportive. The goal is to continuously meet the increasing demands of the fetus, placenta, and mother.
Conclusion
Optimal nutrition during pregnancy is a complex and dynamic process requiring a targeted approach. In the European context, there remains a risk of deficiencies in key micronutrients – particularly folic acid, iron, iodine, vitamin D, and omega-3 fatty acids. The needs for these and other nutrients significantly change across trimesters in line with maternal and fetal physiology. Diet alone often cannot meet these nutritional demands, which is why personalized supplementation with high-quality products is often essential for a healthy pregnancy.
Key Takeaways
General Principles of Pregnancy Nutrition:
-
Prioritize a nutrient-rich diet and follow the motto “Nourish for two” (not “eat for two”), focusing on quality and nutrient density rather than quantity.
-
Proper nutrition supports fetal development and reduces the risk of complications (diabetes, anemia, preeclampsia, preterm birth).
-
Pregnancy is a time of increased need for micronutrients, which is often unmet through diet alone. Therefore, supplementation is frequently necessary.
Most Common Nutrient Deficiencies
-
Folic Acid (Vitamin B9): critical in the 1st trimester for neural tube development; supplementation with active methylfolate is recommended for all women planning pregnancy.
-
Iron: needs increase throughout pregnancy. Deficiency may lead to anemia, preterm birth, and low birth weight.
-
Iodine: essential for fetal brain development; deficiency can impair cognitive function and lower IQ.
-
Vitamin D: crucial for bone health, immunity, and may reduce risks of pregnancy complications such as preeclampsia or gestational diabetes; works synergistically with vitamin K2.
-
Omega-3 fatty acids (DHA & EPA): important for brain and eye development and reducing the risk of preterm birth; dietary deficiency is common.
-
Vitamin B12: necessary for cell division, nervous system development, and blood formation; critical for vegetarians and vegans.
Nutrition Priorities by Trimester
1st Trimester: Organogenesis phase – very sensitive period, key micronutrients: folic acid, vitamin B12, iodine, zinc, vitamin B6
2nd Trimester: Period of rapid growth; increased need for: calories, protein, and nutrients: iron, calcium, magnesium, vitamin D, omega-3 fatty acids
3rd Trimester: Fetus grows rapidly, stores nutrients, and maternal demands for calories and protein peak; key nutrients remain: iron, calcium, omega-3, magnesium, vitamin D
References
[1] Sarah C Bath, Janneke Verkaik-Kloosterman, Magalie Sabatier, Sovianne ter Borg, Ans Eilander, Katja Hora, Burcu Aksoy, Nevena Hristozova, Lilou van Lieshout, Halit Tanju Besler, John H Lazarus, A systematic review of iodine intake in children, adults, and pregnant women in Europe—comparison against dietary recommendations and evaluation of dietary iodine sources, Nutrition Reviews, Volume 80, Issue 11, November 2022, Pages 2154–2177, https://doi.org/10.1093/nutrit/nuac032
[2] Omega-3 fatty acid supply in pregnancy for risk reduction of preterm and early preterm birth: A position statement by the European Board and College of Obstetrics and Gynaecology (EBCOG). Savona-Ventura, Charles et al. European Journal of Obstetrics and Gynecology and Reproductive Biology, Volume 295, 124 - 125
[3] Hsu MC, Tung CY, Chen HE. Omega-3 polyunsaturated fatty acid supplementation in prevention and treatment of maternal depression: Putative mechanism and recommendation. J Affect Disord. 2018 Oct 1;238:47-61. doi: 10.1016/j.jad.2018.05.018. Epub 2018 May 16. PMID: 29860183.
