Many people choose to eat a plant-based or vegan diet for ethical, environmental, or health reasons. While major nutrition institutions in the U.S. and Canada endorse a vegan or vegetarian diet as capable of supporting fertility and pregnancy, there are several essential preconception and pregnancy nutrients that are difficult (or impossible) to obtain in sufficient amounts from plant foods, including:

1. Preformed vitamin A (retinol)

2. Vitamin B12

3. Choline 

4. Vitamin K2

5. DHA 

6. Iron 

7. Zinc 

8. Carnitine

The limited availability of these critical nutrients in a vegan diet means that special care must be taken to fill in nutrient gaps when trying to conceive and while pregnant. It is also important to recognize that each person is unique in their ability to digest, assimilate, and utilize nutrients within the body. This means that a plant-based diet may not be able to meet every person’s needs, even with supplementation. In this article, we discuss each of the above nutrients, their importance for fertility and pregnancy, and ways to ensure adequate intake on a vegan diet.

Preformed Vitamin A

What it is:

Vitamin A is a fat-soluble nutrient that is important for eye health, immune function, reproduction, and major organ function. It is important to note that beta-carotene (found mostly in plant foods) is not the same as preformed vitamin A (retinol), which is only found in animal foods like liver, meat, poultry, and dairy products. Beta-carotene can be converted into vitamin A in the body but the conversion is fairly inefficient and varies widely from person to person. It takes anywhere from 10 to 30 carotenoids to make one molecule of vitamin A.

Why it is important for fertility and pregnancy:

Vitamin A is critical to fetal growth and the development of the eyes, face, heart, limbs, and immune system during pregnancy. It is also important to the development and maturation of both sperm and egg cells during preconception and may play a role in fertilization. Studies show that vitamin A may prevent DNA damage in sperm cells, which is important for male fertility. Deficiency of vitamin A during pregnancy has been linked to birth defects in infants.

How to ensure sufficient intake:

Take a high-quality prenatal or multivitamin that contains at least some preformed vitamin A (not just beta-carotene). Do not exceed 5,000 IU per day of preformed vitamin A from supplements, as this may lead to toxicity. You can also encourage vitamin A conversion in your body by increasing your consumption of carotenoids from leafy greens and orange vegetables, like carrots, squash, and sweet potatoes. 

Vitamin B12

What it is:

Vitamin B12 is a water-soluble nutrient that is essential for many important biological functions in the body, including methylation, gene expression, cell differentiation, and nervous system function. B12 deficiency is very common in those eating a plant-based diet, with an average prevalence among pregnant vegetarian women of 62% (deficiency in vegan women may be even higher). This is due to the fact that B12 is only found in animal foods, such as red meat, seafood, poultry, eggs, and dairy products. 

Why it is important for fertility and pregnancy:

B12 deficiency can cause anemia and it has been linked to impaired female fertility, poorer outcomes in fertility treatment, and early pregnancy loss. B12 levels are also associated with male fertility. Higher levels correlate with better sperm quality parameters in men, including higher sperm count, motility, and morphology, and lower levels of sperm DNA damage. During pregnancy, B12 deficiency is associated with neural tube defects, miscarriage, preterm delivery, and low birth weight.

How to ensure sufficient intake:

Supplement with at least 300mcg per day or 2000mcg per week, preferably in the form of methylcobalamin (which is the most bioavailable for the body). This is much more than what is found in a typical prenatal or multivitamin. If you have a known MTHFR genetic variant, you may need more B12 than this. It is wise to work with your doctor to have your levels tested and create a supplementation plan that will meet your individual needs.

Choline

What it is:

Choline is a B-vitamin relative and has a similar function to folate in the body. It is important to methylation, mental health, digestion, liver function, and cell membrane formation. It is found mostly in animal foods like eggs and liver, with only very small amounts found in plant foods. 

Why it is important to fertility and pregnancy:

Choline is very important to your baby's brain development during early pregnancy, so it is crucial to ensure adequate intake during preconception. Similar to folate, choline has the ability to prevent neural tube defects (birth defects of the brain, spine, or spinal cord) in infants. It has also been shown to support placental function and may even help prevent preeclampsia. Choline is used in certain important metabolic pathways (such as methylation) in the body and women with MTHFR or PEMT genetic variations have been shown to have increased needs for choline.

How to ensure sufficient intake:

Take a choline supplement of at least 550mg per day and up to 1000mg or more if you have a known MTHFR or PEMT genetic variant. Most prenatal and multivitamins do not contain choline so look for choline bitartrate or sunflower lecithin (phosphatidylcholine) in a separate supplement.

Vitamin K2

What it is:

K2 is a fat-soluble nutrient found almost exclusively in animal foods, like full-fat dairy, eggs, and liver. The only plant source of K2 comes from select fermented foods, such as natto. It works together with calcium, magnesium, and vitamin D to ensure proper use of calcium in the body.

Why it is important to fertility and pregnancy:

K2 is essential to fetal bone development and it also helps maintain maternal bone density during pregnancy. Studies also show that K2 helps improve insulin sensitivity and blood sugar control, which is critically important for fertility in both partners and for women during pregnancy. There are even some preliminary animal studies that suggest that K2 may be important to early embryo development, which means you need to ensure you are sufficient in K2 before pregnancy to support development during those first critical weeks.

How to ensure sufficient intake:

Take a vitamin K2 supplement of at least 100mcg per day. Most prenatal and multivitamins do not have K2 in them. Ensure you are also supplementing with calcium and vitamin D to receive the full benefit of vitamin K2.

DHA

What it is:

DHA is an essential omega-3 fatty acid that is important to cell membrane formation, immune function, and gene regulation. It is found primarily in fatty fish, pastured egg yolks, and grass-fed beef. The only significant plant source of DHA is algae. 

Why it is important to fertility and pregnancy:

DHA is critical to fetal brain and eye development during pregnancy and also protects the brain from inflammation and damage. Studies show that DHA intake during preconception may be able to improve egg and sperm quality and contribute to better immune system regulation and lower levels of inflammation in both partners. During pregnancy, research suggests that DHA supplementation may help prevent preeclampsia and preterm delivery. DHA has also been shown to have a positive impact on mood stabilization and may even help prevent postpartum depression.

How to ensure sufficient intake:

Take an algae-based DHA supplement of at least 1000mg (combined DHA and EPA). Algae is the only significant plant source of DHA.

Iron

What it is:

Iron is an essential mineral that is critical to hemoglobin formation in red blood cells and carries oxygen through the blood stream. It is found in two different forms in food: heme and non-heme. Heme iron is easily absorbed by the body and is found only in animal foods, such as red meat, liver, poultry, and seafood. Non-heme iron is found in whole grains, legumes, nuts, seeds, and leafy greens. However, iron is not as well-absorbed from plant foods due to the presence of fiber and phytic acid in these foods.

Why it is important to fertility and pregnancy:

Studies have shown that iron deficiency may cause fertility problems in women by disrupting ovulation and that iron supplementation reduces the risk of ovulatory infertility. Anemia caused by severe iron deficiency may affect fertility by reducing oxygen delivery to the ovaries and uterus, impairing their function. Iron is also critically important during pregnancy, allowing for the necessary expansion of the maternal blood supply, aiding development of the placenta, and providing hemoglobin to the growing fetus. Iron deficiency during pregnancy is associated with increased risk of preterm birth, stillbirth, and low birth weight. Iron is also important for fetal brain development and maternal deficiency has been linked to cognitive delays in infants.

How to ensure sufficient intake:

It is recommended to have your doctor evaluate your iron status by testing ferritin levels (stored iron) in the blood. This will help determine how much iron you need to supplement with during preconception and pregnancy. It is likely that you will need at least 27mg per day, possibly more if you are currently deficient. Most prenatal vitamins do contain iron and each brand differs in the amount included. If your prenatal does not contain iron, you will need a separate supplement.

Zinc

What it is:

Zinc is a trace mineral that is found in both animal foods (red meat, oysters, shellfish) and plant foods (nuts, seeds, legumes). However, similar to iron, zinc absorption from plant foods is inhibited by the presence of fiber and phytic acid, making it difficult to get sufficient zinc from plants alone.

Why it is important to fertility and pregnancy:

Zinc is absolutely crucial to male fertility during preconception, affecting testosterone production and sperm concentration, motility, and DNA quality. It has also been found to affect female fertility and is associated with egg maturation and development, fertilization and embryo growth, sex hormone production and metabolism, and thyroid hormone conversion. Zinc acts as an anti-inflammatory and antioxidant nutrient, which helps protect both egg and sperm cells from damage. New studies are showing that even short periods of zinc deficiency during preconception can affect fertility months later, making it very important to optimize zinc intake before pregnancy.

 Zinc deficiency during pregnancy has been linked to fetal growth restriction, neural tube defects, miscarriage, stillbirth, and preterm delivery. Maternal zinc deficiency during pregnancy has also been linked to adverse health outcomes for children, such as immune system issues, behavioral abnormalities, and blood pressure problems.

How to ensure sufficient intake:

Take a high-quality prenatal or multivitamin that contains at least 11mg of zinc. If you are deficient, you may temporarily need more zinc that what is found in your daily vitamin. If you suspect deficiency, work with your doctor to optimize a short-term supplementation plan to bring your levels up. Long-term supplementation with too much zinc can deplete other minerals in the body, such as copper.

Carnitine

What it is:

Carnitine is a product derived from amino acids (protein building blocks) and it is used in nearly every cell of the body. It is important for cellular energy production and helps transport fatty acids into cells to be burned as fuel. Carnitine is found primarily in animal foods like red meat and dairy. Although carnitine can be produced by the body from amino acids, those on a plant-based diet may still be deficient due to lower protein intake coupled with inefficient production.

Why it is important to fertility and pregnancy:

Studies have shown that it is supportive of both egg and sperm cell maturation and DNA integrity. As an antioxidant nutrient, it can help protect cells from oxidative damage and death. Carnitine also has a positive effect on sperm count, motility, and morphology. In women, carnitine has been shown to help balance sex hormone levels and improve egg quality. Carnitine can also help with blood sugar regulation and insulin resistance, as it aids the body in using fats for fuel.

How to ensure sufficient intake:

Take an L-carnitine supplement of at least 250mg per day. Prenatal and multivitamins are very unlikely to contain L-carnitine so you will need a separate supplement.