Vitamin D3 and Pregnancy: All You Need to Know

Hillary Bennetts

Table of contents

  • Intro
  • The Importance of Vitamin D
  • Can I Get Enough Vitamin D Through Diet?
  • Taking Supplements
  • What Other Pregnancy Supplements Should I Take?

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Vitamin D3 and Pregnancy: All You Need to Know

Vitamin D gets attention for its benefits to bone health and immune health. But the truth is, Vitamin D3 during pregnancy is critical to both a mother and a baby’s health.

But we never share nutrition knowledge without context. So why do mothers and babies need Vitamin D?  What happens when a mother doesn’t get enough? How much is needed? Where can you get it? Is it safe to supplement? And are all supplements the same? We’re answering these questions and more in this article. 

The Importance of Vitamin D

Pregnant or not, we all need Vitamin D. It promotes calcium absorption in the gut and helps to maintain adequate blood calcium and phosphate concentrations for bone health. It also supports normal neuromuscular and immune function and glucose metabolism.

But Vitamin D is especially important in pregnancy as research suggests that adequate Vitamin D levels during pregnancy helps support the health of both mothers and babies.

Is It Safe To Take Vitamin D While pregnant?

Unless you’ve been advised otherwise by your healthcare provider, Vitamin D supplements are safe to take while you’re pregnant and breastfeeding. You can also request a Vitamin D test from your OB-GYN or midwife during pregnancy to confirm your levels and determine appropriate supplementation.

Can I Get Enough Vitamin D Through Diet?

Food sources of Vitamin D are limited. A few options include beef liver, fatty fish (salmon, mackerel, and sardines), egg yolks, and wild mushrooms. But it's unlikely that you could meet your Vitamin D needs through food alone. For example, one egg yolk contains only 37 IU of Vitamin D, a very small contribution to your daily requirement.

Another way to get Vitamin D is through sunlight. Our body makes Vitamin D when our skin is exposed to the sun. However, several factors influence how much Vitamin D you actually get from the sun, including the following:

  • Where we live: This includes things like latitude, altitude, and pollution. Except during the summer months, the skin makes little Vitamin D from the sun at latitudes above 37 degrees north, which includes about two-thirds of the United States, basically anything north of Arizona, Texas, or North Carolina. Higher altitudes have greater sun exposure, and areas of greater pollution have less sun exposure.
  • How much sun we get: Not just how much we’re outside each day, but how much skin is exposed and how much sunscreen we use)
  • The pigment of our skin: Darker skin contains more melanin, which means it is more effective at blocking UV-B rays, so less vitamin D will be absorbed.)

Taking Supplements

So if getting Vitamin D from food and the sun is unreliable, should you supplement? For most people, the answer is yes. We explore more below.

How Much Should I Take in Pregnancy?

Currently, the recommended daily allowance RDA for Vitamin D is set at 600 IU per day for pregnancy. However, numerous studies have shown that this amount is too low and consistently results in Vitamin D deficiency, particularly in women of color.

Unfortunately, despite a wide body of recent research indicating that sufficient Vitamin D levels can reduce the risk of pregnancy complications and promote optimal fetal development, official recommendations for Vitamin D requirements in pregnancy have not been updated.

In fact, several studies conducted on Vitamin D supplementation in pregnant women show that an amount closer to 4,000 IU daily is not only safe, but optimal during pregnancy and that the current RDA of 600 IU is insufficient.  

For example, in one double-blind, randomized controlled trial, pregnant women received either 400 IU, 2,000 IU, or 4,000 IU of Vitamin D3 daily starting between 12 and 16 weeks gestation until delivery. Only 50% of mothers in the group that received the lowest dose (400 IU) had sufficient Vitamin D levels at delivery (and only 20% of Black women in this group had sufficient levels. At the other end of the spectrum, of the women who received the highest dose (4,000 IU), 82% had adequate Vitamin D levels at delivery. In addition, adequate maternal vitamin D levels predicted newborn vitamin D levels (meaning higher dose supplementation significantly reduced the risk of newborn vitamin D deficiency). The researchers found no adverse events linked to any level of Vitamin D supplementation tested and concluded that 4,000 IU per day for pregnant women is safe and was the most effective in achieving Vitamin D sufficiency in all pregnant women and their newborns, regardless of race. 

However, while research suggests 4,000 IU likely provides a sufficient amount for pregnancy, just as with other recommendations, this isn’t a foolproof or one-size-fits-all amount. This is because a number of factors affect how much Vitamin D a woman needs, including her Vitamin D levels prior to becoming pregnant.

In other words, a dose of 4,000 IU comes much closer to meeting your needs during pregnancy than the current RDA of 600 IU, but the only way to truly know what your levels are and how much more you may need is to test. 

Most people, especially during pregnancy and postpartum, could benefit from Vitamin D supplementation.

Needed’s Prenatal Multi contains a supportive 4,000 IU of Vitamin D. Needed’s Prenatal Multi Essentials contains 2,000 IU. If more is needed, or if you are taking a different prenatal with a lower amount of Vitamin D, you can add on Needed’s Prenatal Vitamin D3/K2. The capsules are small in size and easy to swallow. They provide 2,000 IU of Vitamin D3 for flexible dosing, plus 45 mcg of Vitamin K2 for optimal absorption.

Vitamin D in the First Trimester

The First Trimester can be a sensitive time. Many mamas are quite cautious about what they consume, and also a bit limited in what they can stomach due to nausea and food aversions. It’s unlikely that you’ll be up for eating liver in the First Trimester (but if you are, 

What Other Pregnancy Supplements Should I Take?

Vitamin D is one of many important nutrients you need during pregnancy. Pregnancy is one of the most nutritionally demanding times in your life, and nutrition during pregnancy has long lasting effects on your health and the health of your baby. 

So while Vitamin D during pregnancy is important, Vitamin D alone isn’t enough. Look for a comprehensive prenatal vitamin with optimal forms and dosages of each of the nutrients included. And be sure to consider what isn’t included too - unwanted additives and fillers, and nutrients that are better taken separately, like Iron and Omega-3s. 

Needed spent over three years developing its Prenatal Multi and continues to perfect it's nutritional system through ongoing clinical insights and research. Learn more here.



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Hillary Bennetts, Nutritionist

Hillary Bennetts is a nutritionist and business consultant focusing on prenatal and postpartum health. In addition to nutrition consulting, she provides business consulting and content creation for companies in the health and wellness industry. Hillary spent almost a decade in corporate consulting before shifting gears to combine her lifelong passion for health and wellness with her business background and nutrition education.