Infertility rates are rising. In 2019 UK birth rates hit a new low for the fourth consecutive year, according to the Office for National Statistics (ONS), and the UK is not alone - this fact is echoed throughout the developed world.
So, when it comes to trying to conceive, what can we do to help boost fertility?
With over 25 years’ experience in fertility, women’s health, gynaecology, sexual and contraceptive health, Independent Fertility Nurse Consultant Kate Davies, is an expert in natural fertility and here she shares her evidence-based guide to fertility supplements.
If you’re trying to conceive, it’s likely that you’ve started to look into which supplements you should take to help boost your fertility. I find that women can be taking a huge number of supplements, from the weird to the wonderful, in the hope that one might just be the missing key to unlocking their fertility struggle.
You may have been recommended specific supplements by a friend or heard mention of supplements that will improve fertility on forums and online communities, but do these fertility supplements really work and where is the evidence to support their use in fertility?
Why, when it comes to supplements, is evidence important?
Evidence-based practice is where medical treatments, medicines or supplements have been thoroughly assessed to show improvement to patient outcomes.
Not all supplements have the research to show that they can make a positive outcome to your health or fertility and that’s why it’s important to do your homework and make the right choices on the supplements you decide to take.
If you enjoy a vegetarian or vegan diet, it’s even more important that you consider the supplements you need to boost your nutritional intake.
This evidence-based guide is the perfect place to start in understanding which nutrients – and therefore, which supplements – are recommended to take and the research that supports their use in fertility.
- Vitamin D
- Folic Acid
Vitamin D is often referred to as the ‘sunshine vitamin’ because it’s produced by the body’s reaction to the skin’s exposure to the sun. However, during the autumn and winter months, it becomes harder for us to get what we need from the sun’s rays alone, and Public Health England (PHE) recommends that every adult should consider taking a daily supplement of 10μg.
There is good evidence to suggest that vitamin D assists in human reproduction, with an extensive literature review finding that vitamin D plays an important role in regulating sex hormones. It may also play a part in regulating the symptoms associated with Polycystic Ovarian Syndrome (PCOS) and help in reducing inflammation in women with endometriosis.
So, vitamin D is a good all-rounder when it comes to fertility, and not only for women. Evidence suggests that vitamin D also has a beneficial effect on sperm quality and that supplementation may improve sperm mobility.
It is well known that selenium is an essential nutrient for sperm health, but what about selenium as a supplement for women?
A study looking at selenium in early pregnancy and the association with fertility found that lower selenium concentrations were associated with a longer time to conception, and importantly, it also showed a greater risk of infertility among study participants.
The recommended daily amount of selenium is 75μg for men and 60μg for women and whilst brazil nuts, seafood, poultry, and eggs are all good sources of selenium, supplementation is important if you don’t think you can get the full recommended amount from your diet.
Like selenium, it is well documented that the mineral zinc has great benefits for sperm health and low levels can be one of the causes of sperm abnormalities. Interestingly, women with lower zinc levels take longer to conceive than those with an adequate level.
To obtain the recommended 9.5mg per day for men and 7mg per day for women, zinc can be found through a combination of food sources such as meats, dairy foods, breads and wheatgerm, as well as through supplementation.
A mineral of crucial importance to cell development, iron is often related to deficiencies experienced during pregnancy, however do we need to consider iron when it comes to fertility in women?
A large prospective study of over 18,000 women has concluded that yes, we do, and especially when it comes to ovulation. This study found that women who consumed iron supplements had a significantly lower risk of developing ovulatory disorders than women who did not take supplementation.
Women of childbearing age should take 14.8mgs of iron per day. As well as supplementing, including iron-rich foods such as red meat, beans, nuts and dried apricots, fortified breakfast cereals and green leafy vegetables is recommended.
Iodine might not necessarily be a nutrient that springs to mind when considering your fertility supplements, but it’s importance should not be underestimated.
Deficiency is common in women of childbearing age and a 2018 study found that women with a moderate to severe iodine deficiency had a 46% reduction in their ability to conceive.
These findings are supported in a large study of over 78,000 pregnancies, where low iodine intake was associated with increased infertility and reduced foetal growth, increased pre-eclampsia and preterm delivery.
Good sources of iodine include fish, shellfish, and some plant foods such as grains and cereals. The levels of iodine in plant-based food varies and therefore it is worth considering supplementing to ensure you reach the recommended daily intake of 140μg a day.
A vital nutrient when trying to conceive and during the first 12 weeks of pregnancy, folic acid helps to increase maternal folate levels and reduces the risk of foetal neural tube development problems, such as spina bifida. However, did you know that folic acid is often added to fertility supplements for men, too?
Over the years, various research has shown that low levels of folic acid are associated with poor sperm health. However, more research is needed in this area to fully understand if there are benefits for men supplementing with folic acid, as a 2020 study refutes this view.
Women should supplement with 400μg of folic acid daily and it is advisable to start as soon, and if not a little before, you start trying to conceive.
I hope this guide shows that supplements are important for your fertility and that taking the time to research the evidence surrounding the supplements you choose is vital in helping you to make informed choices.