Sunshine is your best option for getting vitamin D, but it’s likely that your sun exposure isn’t enough. Supplementing 2,000 IU daily of vitamin D is often recommended for pregnant women. Breastfeeding women should take in even more vitamin D.
What is vitamin D and why do I need it?
Vitamin D is a fat-soluble vitamin with a critical role in helping with the absorption of important nutrients such as calcium and iron, making it essential in promoting bone health. It is also important in regulating proper immune function, reducing inflammation, and modulating cell growth.
In pregnancy, vitamin D plays a critical role in transferring calcium to the developing baby, which is necessary for skeletal development. Unfortunately, most pregnant women (and many populations worldwide) are deficient in vitamin D .
Studies have shown that deficiency of vitamin D is linked to an increased risk for preeclampsia, higher rates of cesarean section, and possibly other adverse health outcomes for kids long into their childhood [2, 3, 4]. A recent meta-analysis also points to the correlation between vitamin D supplementation during pregnancy and reduced risk of preeclampsia and low birth weight .
Findings and recommendations around vitamin D continue to evolve (see next section). Despite any uncertainty, we know that having sufficient vitamin D levels prior to conception and maintaining healthy levels during pregnancy is important for proper body function and development.
How much vitamin D do I need?
Guidelines from the National Academy of Medicine (NAM) for vitamin D intake have changed over the years as new analyses and approaches for evaluating sufficiency become available. Currently, the official recommendation from NAM is 600 International Units (IU) of vitamin D daily for everyone between the ages of 1-70, including pregnant and breastfeeding women . The upper intake level is 4,000 IU, which NAM states to be the safe maximum daily intake for vitamin D .
Numerous studies have shown that doses above 600 IU are safe, effective, and necessary in achieving desirable levels of vitamin D in the blood [7, 8, 9]. It was also found that breastfeeding mothers taking 2,000 IU had slightly elevated vitamin D levels in their milk, but 4,000 IU was even more beneficial towards increasing the vitamin D levels for their babies . Even higher doses up to 10,000 IU daily are recommended for resolving vitamin D deficiency is adults, despite the UL levels of 4,000 IU .
While official recommendations from NAM have not been updated to reflect these findings, many professionals are now advising that women get 2,000 IU of vitamin D daily during pregnancy and even higher amounts during breastfeeding.
Can I get enough vitamin D from food?
Very few foods contain substantial amounts of vitamin D. One of the highest contents is found in mushrooms that are grown with ultraviolet light, containing as much as 1,110 IU per cup . Many types of cereal, soy and nut milk, tofu, and juices are fortified with vitamin D, providing somewhere between 100-200 IU . In general, getting sufficient vitamin D from food is a challenge for people on any diet.
Can I get enough vitamin D from the sun?
Our best source of vitamin D is the sun. We have receptors all over our skin that absorb UVB rays from sunlight but sunblock prevents most of that absorption. Many other factors impact how much vitamin D you’re actually able to get from the sun, including your skin color, where you live relative to the equator, the season, time of day, and how much skin is actually exposed.
For example, if you live in Los Angeles, 15-30 minutes of direct sun exposure is probably sufficient for your body’s needs of vitamin D. If you live further north, you would require longer sun exposure and are likely to need supplementation in the winter months when sunlight is limited.
You cannot overdose on vitamin D from the sun, your skin will simply absorb less if you already have enough. However, we know that too much sun exposure increases our risk of skin cancer.
I’ve come across many guidelines for ensuring that you get sufficient (but not too much) vitamin D from the sun, including timing your walks and assessing the length of your shadow. Browsing through numerous calculators and charts, I couldn’t find reliable and consistent data. And to be honest, I have yet to meet anyone who tracks their walks based on the time of day and season, then stops to apply sunscreen. Sensible sun exposure is the best approach: spend time outside daily, protect your skin as necessary, and avoid sunburns.
Yes, you can get plenty of vitamin D from the sun – our ancestors certainly did. But given our modern lifestyles (the fact that we wear clothes, for one, and sit indoors most of the time), sunlight exposure is not the way for many of us to get sufficient amounts of vitamin D. That leaves us with the next best option: supplementation.
Which supplement is best: vitamin D2 or D3?
Vitamin D comes in two forms: D2 (ergocalciferol) is made by fungi and D3 (cholecalciferol) is made by plants and animals. Research has shown that supplementation of both, vitamin D2 and D3, effectively increases the levels of vitamin D in the body, when taken daily is standard doses . However, when taken in large doses on a weekly or monthly basis by individuals with a significant deficiency, supplementing with vitamin D3 appears to be more effective .
Another interesting consideration is that levels of vitamin D in our blood are linked to longevity. A large review of numerous research studies has shown that supplementing with vitamin D3 leads to increased lifespans, whereas vitamin D2 supplementation has no impact .
Given the current research, it is generally accepted that supplementation with vitamin D3 is preferred to vitamin D2.
Vegan supplements with vitamin D
Most multivitamins and pretty much all prenatal vitamins contain some amount of vitamin D. Majority of them contain vitamin D3 derived from lanolin (sheep’s wool). For vegan supplements, look on the label for cholecalciferol sourced from lichen or Vitashine, which is a branded form.
For supplementation during pregnancy, here is a list of prenatal vitamins that contain vegan forms of vitamin D:
If you choose to supplement vitamin D3 on its own, here is a list of vegan options that contain less than 4000 IU (the upper intake level):
Nordic Naturals Vitamin D3 Vegan (1000 IU)
Garden of Life mykind Vegan D3 (2000 IU)
Ora Organic Vegan Vitamin D3 (2000 IU)
NATURELO Vitamin D3 (2500 IU)
Doctor’s Best Vitamin D3 (2500 IU)
DailyD Vegan Vitamin D3 (2500 IU)
Many other supplements are available that contain vitamin D with B12 or calcium or vitamin K2, among others. When combining supplements be sure to take a look at the total amounts you’re taking of each nutrient to ensure that you are not exceeding any toxicity levels. It is, of course, recommended to discuss all of this with your healthcare provider.
- Direct sun exposure and some select foods provide vitamin D, but likely not enough.
- Supplement with 2,000 IU vitamin D daily while pregnant and possibly higher while breastfeeding.
- Select a vegan form of vitamin D3 derived from lichen, commonly branded as Vitashine.