Recent studies on vitamin D in pregnancy are confirming that mamas should be taking more vitamin D than they probably think—and definitely more than their prenatal vitamins contain.  


The typical prenatal vitamin has 400 IU of vitamin D, while many experts are now recommending that pregnant mamas should be getting 4000 IU of vitamin D per day.  That’s a big difference—10 times more, in fact!   Why the new recommendation?  Studies are suggesting that higher levels of vitamin D in pregnancy result in decreased risk of preterm delivery, gestational diabetes, hypertension, and preeclampsia.  And for the baby, mama having an increased level of vitamin D has been shown to result in improved cognitive and motor development, decreased asthma, decreased heart disease, and decreased low birth weight.  Unfortunately, many mamas enter pregnancy with inadequate vitamin D levels that are then worsened by pregnancy itself, so it’s important to know your vitamin D status—throughout your life, but especially before conceiving, during pregnancy, and during your postpartum recovery.

Vitamin D plays a multitude of roles in our bodies, some of which have only recently been discovered.  We know that vitamin D is necessary for absorption of calcium and phosphorus from the intestinal tract and that it contributes to maintaining strong bones and decreasing fracture risk and osteoporosis.  Other suspected roles of vitamin D include prevention of cancers, decrease in autoimmune diseases, decrease in heart disease, and protection from general infections.  Vitamin D appears to be important in boosting our immune systems and giving us (and our babies) better overall health.

As you’re considering how to get that 4000 IU per day of vitamin D in, here are a few things to think about:  Vitamin D is available to us through our diet, through skin exposure to UV-B rays in sunlight, and through vitamin supplements.  The best dietary sources for vitamin D are fatty fish (salmon, sardines, anchovies) and fortified milk.  One 3.5oz serving of salmon provides 360 IU, and fortified milk contains 100 IU per 8oz.  Smaller amounts of vitamin D are also found in fortified cereals, egg yolks, cheese, and some mushrooms.  Sunlight exposure is not recommended as a primary source for vitamin D due to association of UV rays with skin cancers, such as melanoma.  Taking all of this into account, it’s really almost impossible for a mama to get 4000 IU per day of vitamin D without taking a supplement—unless you’re planning to eat about 10 servings of salmon each day (and if you are, then we’re going to need to talk about mercury exposure)!

So, modern mamas, do you know your vitamin D level?  It’s an easy blood test that your care provider can order for you.  The specific value that should be checked is a vitamin D 25OH level.  Unfortunately, there’s no clear definition for what the best level in pregnancy is, but general consensus is that any level < 20ng/mL is definitely inadequate, <32ng/mL is probably inadequate, and at least 50ng/mL is likely a good goal.  Studies do show that the earlier vitamin D supplementation is started in pregnancy, the better—in fact, vitamin D supplementation should be started prior to conception, when possible.  Be sure that the vitamin D formulation you’re taking is vitamin D3, rather than D2, as the D3 is better-absorbed. Also, keep in mind that vitamin D is best absorbed when taken with foods containing some fat or oil.

Culled from Michelle Bennet MD March 2015 post on

About the author

Kris Ero

Professionally known as The Wellness Boss, Kris is a trained wellness coach focused primarily on promoting corporate wellness. She is also a Child and Family Wellness Advocate and has appeared on several radio and tv shows. As a wellness entrepreneur, she runs several wellness initiatives. In her spare time, she loves to catch up on her reading and tv shows. An avid foodie, she seeks healthier ways of enjoying what she loves.

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