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  • Writer's pictureIsobel Austin-Little


First things first. When it comes to making a baby, the health of the mother and father at conception has a significant role to play in the health of the offspring. When couples start trying for a baby with nutrient deficiencies, they are more likely to face difficulties conceiving or may experience problems throughout pregnancy. Not to mention the impact it can have on the baby, with studies showing how it can predispose offspring to chronic conditions later in life such as obesity, diabetes, cardiovascular disease, and neurodevelopmental delays.

Conception, pregnancy and labour are extremely energy-demanding processes that require a diet abundant in macro and micronutrients. When adopting a diet that restricts food groups, it's imperative to ensure that those removed food groups are substituted. So let’s take a look at those nutrients that may be compromised with a vegetarian and vegan diet.


Protein provides the building blocks to healthy eggs, sperm and hormones, all of which are required for conception to occur. Sources such as fish, lean meat, eggs and soya contain complete protein, whereas plant sources are not all complete. A complete protein is a food source that contains all the essential amino acids that the body needs to function. Vegans and veggies should be aware of their plant protein sources and the best way to combine them to meet the needs of the body. I have included examples of these below.

How much protein do you need daily? The Reference Nutrient Intake (RNI) for an average adult is set at 0.75g of protein per kg of body weight per day. So, for example, an adult weighing 60kg needs 60 x 0.75g per day, which is 45g.

Plant protein sources:

  • Plant proteins such as beans, lentils, nuts and whole grains

  • Amaranth, quinoa, hemp seed and chia seed are also wonderful and complete source of protein

  • Soy products, but the quality is key here. Only purchase organic tempeh or organic tofu

Combining proteins:

  • Beans with nuts or seeds (salad with chickpeas and sunflower seeds)

  • Nuts or seeds with whole grains (nut butter on whole-wheat toast)

  • Whole grains with beans (black beans and rice; hummus and pita; bean-based chilli and crackers


This vitamin is essential for DNA and RNA replication and is important in preventing nerve damage, with deficiency linked to long term irreversible symptoms, including numbness and increased risk of a stroke. Deficiency can also lead to temporary infertility.

B12 food sources are meats, fish, dairy and eggs. It's recommended that men and women consume 1.5 mcg/d of B12 daily, and supplementation is necessary for vegans/vegetarians in order to meet the body's needs. Nutritional yeast is a great kitchen cupboard staple. It is a complete source of plant protein providing the body with 14 grams of protein and 2.2 mcg of B12.


Zinc is a cofactor in over 200 processes in the body. It possesses antioxidant properties that are specific for the reproductive organs, protecting the egg and sperm from oxidative damage. This mineral actually facilitates reproduction, ovulation and fertilisation, so we don't want our diet to be lacking in it! Deficiency may interfere with the production and secretion of essential sex hormones. It may also increase the risk of miscarriage. It is important to note that the oral contraceptive pill and the copper coil can disrupt zinc levels.

Plant-based foods high in zinc include seeds, nuts, lentils, yoghurt, oatmeal, and mushrooms and women need about 7 mg/d and men need 9.5 mg/d.


Iron is important in the formation of red blood cells, delivering oxygen to tissue, it's a cofactor in the replication of our genes, and it aids the development of the growing baby. There are two forms of iron, heme (from meat) and non-heme (plants), with heme from meat sources being the more absorbable form. Deficiency can cause the absence of periods (amenorrhea), a lack of ovulation (anovulation) or weak ovulation whereby not enough progesterone is created to maintain a healthy pregnancy. Deficiency is more common in women also because of menstruation, where there is blood loss. For all women, especially those who follow a vegan/vegetarian diet, it is imperative to replenish the body with blood-enriched foods post-period or supplement where necessary.

Women need around 14.8mg/d and men need 8.7mg/d. Plant-based sources of iron, such as beans, lentils, nuts and green vegetables. Including a source of vitamin C with meals, such as citrus fruits, peppers, can increase the absorption of non-heme iron from the diet.


Calcium is important for the development of eggs, sperm quality, fertilisation and bone formation of the mother and the child. Plant-based sources are edamame beans, seeds such as sesame seed, nuts like almonds, and dark leafy greens. The recommended intake for women is 700mg/d for men and women.


Iodine is an important player in thyroid health, and optimal thyroid health is linked to healthy conception, pregnancy as well as recovery postpartum. Low iodine levels can also negatively impact the development of the baby's nervous system. Men and women need around 140mcg/d and vegan sources are very limited to seaweed or iodised salt as iodine is primarily found in fish and dairy products.


Omega-3 fatty acids are considered essential as the body cannot synthesise them, and therefore they must be consumed in the diet. Omega's are anti-inflammatory, they support blood flow and improve endometrial function. They are also essential for the healthy development of the baby's brain and eyes during pregnancy. There are different forms of these fats, found in different foods. These Include.

Eicosapentaenoic acid EPA / Docosahexaenoic acid DHA - Oily fish and Algae

Alpha-linolenic acid (ALA) - flax seeds, flaxseed oil, canola oil, chia seeds, walnuts, hemp seeds, and soybeans.

The body has to convert ALA to DHA/EPA in order to use it, however, the conversion rate is really low, meaning you would have to eat crazy amounts of ALA in order to get enough DHA. This needs to be factored in when on a vegan or vegetarian diet, and appropriate supplementation may be beneficial, for example from a good quality Algae oil.


There are more and more studies being published that show the amazing benefits of vitamin D on pretty much all areas of our health, as well as fertility. Vitamin D plays a role in calcium homeostasis and the modulation of healthy bones for mum and baby, it's important for the activation of the immune system and is involved in fertilisation and the acceptance of the sperm by the oocyte. Vitamin D deficiency is now considered a marker for reduced fertility and various adverse pregnancy outcomes. Men and women need 10ug/d of vitamin D daily. Ultimately the best source of vitamin D is the sun but let's be honest, that is not something we see too much of in the UK. Therefore supplementation is recommended by Public Health England to avoid deficiency. Plant-based sources include mushrooms and fortified foods. I would always recommend getting levels checked, and then supplementing accordingly.


As well as making sure you're consuming all those wonderful whole foods to get in these nutrients that might be compromised in a vegan/veggie diet, it's also important to be aware of those highly-processed vegan foods. These include the ever-growing selection of vegan meats, vegan cheeses and vegan desserts. Vegan and plant-based labels don’t always mean it is a healthier option.


If you are veggie or vegan and you are thinking about trying to conceive, have a look at your diet, and make sure you and your partner are both getting what you need daily in terms of nutrients. A plant-based diet can be really beneficial for your health when done right, but done wrong, it can compromise your ability to conceive. Every individual is unique, and what works for one person, might not work for another. If you are thinking about going vegan for the planet, make sure you are also thinking about your health and diet too.

A few things to consider.

  • Visit a GP to carry out tests to check for key deficiencies.

  • Plan your meals to make sure you are capturing all the macro/micronutrients your body needs.

  • Consume whole foods (nuts, seeds, beans, legumes, veg, olive oil, whole grains, herbs and spices)

  • Avoid processed pre-packaged options (frozen meals, ready meals) and sugary energy bars (they contain hidden sugars

  • Take a good prenatal multi-nutrient to cover your bases

If you are concerned about your diet and are keen to get help, seeking professional guidance from your GP or a Nutritionist is really important to support your individual needs. If you are interested in a consultation, I offer a free 30-minute consultation ahead of each booking, you can get in touch with me here.

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