Vitamin D for fertility and pregnancy

Did you know that up to 90% of women trying to conceive or already pregnant aren’t getting enough vitamin D?

This essential nutrient plays a critical role in fertility, pregnancy, and your baby’s future health - yet most women aren’t getting the amount they need. And many of us don’t realise we may be deficient.

Understanding how vitamin D supports your body and how to optimise your levels can make a significant difference in your journey to conception and a healthy pregnancy. Here’s what you need to know about vitamin D and what to do to make sure you’re getting enough.

Why is vitamin D so important for fertility and pregnancy?

Vitamin D is often associated with bone health, but its role goes far beyond that - especially during preconception and pregnancy.

Vitamin D:

• Supports healthy ovulation & fertility.Vitamin D influences reproductive hormones, and studies suggest that adequate levels can improve fertility outcomes.

• Critical for baby’s development. It plays a key role in your baby’s developing bones and immune system - and can reduce the risk of infections during pregnancy.

• Reduces risk of pregnancy complications. Low levels of vitamin D have been associated with an increased risk of gestational diabetes, preeclampsia and preterm birth.

• May influence your baby’s future health. Emerging research suggests that vitamin D levels during pregnancy could impact your child’s long-term health, including their risk of conditions like asthma and autoimmune diseases.

Why aren't we getting enough vitamin D?

Vitamin D is unique because our bodies produce it in response to sunlight exposure.

However, if you live in a country with limited sunshine (like here in the UK!) - especially during winter - you're probably not producing enough naturally.

Food sources of vitamin D, such as fatty fish, egg yolks and fortified dairy products, can help - but they don’t usually provide enough to meet your daily needs.

Public health guidelines recommend 10mcg (400IU) per day, but research suggests that this isn't enough for most women, especially for fertility and pregnancy. Many of us need higher doses to achieve sufficient vitamin D status.

How can you make sure you're meeting your vitamin D needs?

• Check your vitamin D levels – A simple blood test from your GP or midwife can tell you if you need to supplement more.

• Adjust your intake if needed – If your levels are low, you may need up to 100mcg (4000IU) daily, which is safe and may be beneficial when you're trying to conceive (TTC) and during pregnancy.

• Look for vitamin D3 – D3 (cholecalciferol) is considered the best form, as it’s been shown to be more effective at raising levels than D2.

• Pair it with vitamin K2 – These two vitamins work together to help your body use calcium properly and support bone health, so check there's vitamin K2 in your prenatal multivitamin too.

• Check your prenatal supplement – Some contain vitamin D, but often not enough. If needed, take an extra supplement to reach the right amount for you.

• Eat more vitamin D-rich foods – While food alone won’t be enough, including salmon, sardines, egg yolks and fortified dairy or plant milk alternatives can help boost your intake.

Final thoughts

Vitamin D is essential for fertility, pregnancy, and your baby’s health, but most women aren’t getting enough.

A simple blood test can tell you where you stand, and if needed, upping your intake can make a huge difference.

Want help choosing the best prenatal supplements? Grab my Prenatal Supplements Guide ebook for my top unbiased picks.

Do you have another question? Get in touch with me here or on Instagram @prenatalnutritionistclaire