Vegetarian and vegan diets have increased worldwide in the last few decades, according to the knowledge that they might prevent coronary heart disease, cancer, and type 2 diabetes.
VEGETARIANISM AND FERTILITY
The evidence that is currently available suggests that well-planned vegetarian and vegan diets may be considered safe during pregnancy and lactation, but they require a strong awareness for a balanced intake of important nutrients.
Following a vegetarian diet is unlikely to impact your chances of being able to conceive. A well-balanced vegetarian diet that still contains dairy products and other food groups can provide almost all the nutrients one needs to optimize fertility.
If we put it in simple words, eating lots of dairy, whole grains, fruits, and vegetables has nothing to do with your fertility – provided you are well nourished.
VEGAN DIET AND NUTRIENT DEFICIENCIES
This is true even though plant-based diets run the risk of nutritional deficiencies such as those in proteins, iron, vitamin D, calcium, iodine, omega-3, and vitamin B12.
The two most common nutrient deficiencies experienced by those who follow a vegan diet are deficiencies in vitamin B12 and Iron. Vitamin B12 is only found in animal products, whereas the Iron present in vegetables and other plant foods is in a poorly absorbable form. A deficiency of either of these two nutrients could negatively impact the chances of conceiving and maintaining a healthy pregnancy.
Iron Deficiency
Iron deficiency results in reduced red blood cell production and can lead to a reduced supply of oxygen reaching the reproductive organs. Iron deficiency among women who avoid animal products is very common, in fact, one study found that all women who didn’t consume animal products had some degree of iron deficiency. We also know that there is a relationship between reduced iron intake in women and ovulatory infertility (infrequent or irregular ovulation) and therefore a reduced chance of conception. Studies have found that up to a third of vegan males have depleted iron stores, and this deficiency can negatively impact sperm production, contributing to lower quality and a smaller number of sperm being produced.
Vitamin B12 Deficiency
A Vitamin B12 deficiency is very common in vegans, with one study finding that 78% of the vegans tested had inadequate B12 status compared to 0% of meat eaters. B12 plays a key role in DNA production, helping to produce high-quality DNA. Conception is essentially the combining of DNA from a sperm and egg cell and the quality of this DNA is key in promoting conception, both naturally and in assisted conception. In women vitamin B12 deficiency has been found to have a relationship with infertility and miscarriage and one study found that women who had better B12 levels had better embryo quality during IVF. Similarly, a good B12 status in men is known to improve sperm number, motility, and quality. Therefore, a deficiency of B12 could negatively impact male fertility.
DAIRY-FREE DIETS, IODINE DEFICIENCY, AND FEMALE FERTILITY
The consumption of dairy-free foods, such as dairy-free milk, cheese, and ice cream has become increasingly popular, even among those not following a vegan diet. However, dairy products represent the main dietary source of iodine and anyone following a dairy-free diet runs the risk of developing an iodine deficiency.
Iodine is crucially important for women trying to conceive due to its role in the production of thyroid hormone, deficiency of iodine can cause thyroid hormone production to dip. Low levels of thyroid hormones can then have a negative impact on the chances of conceiving and impact foetal development during pregnancy.
During gestation babies’ brain and nervous system development is reliant on thyroid hormones, and iodine deficiency during pregnancy is linked to learning difficulties and lower IQ in offspring. Iodine requirements in pregnancy increase by around 50% because of the importance of thyroid hormone production during this time and unfortunately women who follow a dairy-free diet when trying to conceive and pregnant are at high risk of iodine deficiency.
So, the known health benefits of a vegan diet must be balanced by the risks of developing iron, iodine and B12 deficiencies and the potential negative impact of these deficiencies for reproductive health. When trying to conceive it is important to screen for nutrient deficiencies so that appropriate changes can be made to ensure optimal nutritional status to support egg and sperm quality and increase chances of conception. With an understanding of nutrient status proper nutritional support such as supplementation or adjustment of dietary patterns can be undertaken.
IF YOU’RE PREGNANT: YOUR DIET CHART
If you’re pregnant and a vegetarian or vegan, you need to make sure you get enough iron and vitamin B12, which are mainly found in meat and fish, and vitamin D, calcium, and iodine.
Iron in your diet
Good sources of iron for vegetarians and vegans include:
- pulses
- dark green vegetables
- wholemeal bread and flour
- nuts
- fortified breakfast cereals (with added iron)
- dried fruit, such as apricots
Vitamin B12 in your diet
Good sources of vitamin B12 for vegetarians include milk, cheese, and eggs.
Good sources for vegans include:
- breakfast cereals fortified with vitamin B12
- unsweetened soya drinks fortified with vitamin B12
- yeast extract, such as Marmite, and nutritional yeast flakes which are fortified with vitamin B12
Vitamin D in your diet
From late March or early April until the end of September, most people should be able to get enough vitamin D from sunlight.
Although we get vitamin D from sunlight, vegetarian food sources include:
- egg yolk
- foods fortified with vitamin D, including some breakfast cereals and fat spreads
- dietary supplements
Because vitamin D is found only in a small number of foods, it is difficult to get enough from foods that naturally contain vitamin D and fortified foods alone.
That’s why the government recommends that all adults, including those who are pregnant and breastfeeding, should consider taking a daily supplement containing 10 micrograms of vitamin D during the winter months (October until the end of March).
You may be at particular risk of not having enough vitamin D if:
- you have brown or black skin (for example, if you’re of African, African Caribbean or south Asian origin)
- you cover your skin when outside or spend lots of time indoors
You may need to consider taking a daily supplement of vitamin D all year. Talk to a midwife or doctor for advice.
If you’re vegan, check the label to make sure your vitamin D is suitable for vegans.
Calcium in your diet
If you’re a vegan, you also need to make sure you get enough calcium. This is because non-vegans get most of their calcium from dairy foods.
Good sources of calcium for vegans include:
- dark green leafy vegetables
- pulses
- fortified unsweetened soya, pea and oat drinks
- brown and white bread
- calcium-set tofu
- sesame seeds and tahini
- dried fruit
Talk to your midwife or doctor about how you can get all the nutrients you need for you and your baby.
Iodine in your diet
Good sources of iodine for vegetarians include cow’s milk, dairy products and eggs.
Iodine can also be found in plant foods, such as cereals and grains, but the levels vary depending on the amount of iodine in the soil where the plants are grown.
If you’re vegan then you may want to consider taking an iodine supplement or eating foods fortified with iodine, such as some types of plant-based drinks.
REFERENCE
Mahajani, Kamla, and Vibha Bhatnagar. Comparative Study of Prevalence of Anaemia in Vegetarian and Non Vegetarian Women of Udaipur City, Rajasthan. Journal of Nutrition & Food Sciences S3 (2015).
