As Always, There Are at Least Two in There

Last revision: 08/29/25

By Eugene L. Heyden, RN

It’s quite obvious. You’re having a baby. We’re glad. And we want what you want—a healthy, happy baby. However, did you know that a poorly constructed placenta can cause all sorts of trouble and stand directly in the way? With all the attention on the baby—meeting his or her needs for proper development—we often overlook the needs of “someone” else. You’re not just having a baby; you’re also having a placenta! And just like babies, placentas are part mom and part dad. They should be given cute little names.

The idea that the placenta could cause problems might be surprising. And by “troublemaker,” I mean “troublemaker!” In the worst case, an abnormal placenta could threaten the baby’s life. It might even put the mother’s life at risk. And even if the worst doesn’t happen, an abnormal placenta can lead to complications like preeclampsia, preterm labor, and fetal growth restriction (Sibley, 2017; Wagner and Hollis, 2018).

Clearly, an abnormal placenta—one that has turned to the dark side—is something to avoid. Fortunately, what is good for the baby is also good for the placenta, so creating a healthy placenta might be easier than you think.

The scientists who diligently study these issues also want you to have a healthy placenta. Their research is yielding remarkable discoveries that warrant attention. Unfortunately, since you and your girlfriends are having babies so quickly, our doctors seem to be struggling to keep up with the latest findings. After much delay, they finally started paying attention to folic acid for preventing birth defects—but it took about 25 years of delay and neglect before folic acid supplementation became standard practice. So, “Mom,” it’s up to you to become cutting-edge. Pay close attention to the following:

“Adequate vitamin D intake is essential for maternal and fetal health during pregnancy, and epidemiological data indicate that many pregnant women have sub-optimal vitamin D levels. Notably, vitamin D deficiency correlates with preeclampsia, gestational diabetes mellitus, and bacterial vaginosis, and an increased risk for C-section delivery. Recent work emphasizes the importance of nonclassical roles of vitamin D in pregnancy and the placenta. The placenta produces and responds to vitamin D where vitamin D functions as a modulator of implantation, cytokine production and the immune response to infection.” (Shin et al., 2010, emphasis added)

Relevant to the issues at hand, scientists have found that vitamin D deficiency negatively impacts placental health. It turns out that vitamin D is a vital nutrient; it is a steroid hormone we cannot live without, and the placenta relies heavily on it, so you can have the baby of your dreams. Normal placental development depends on sufficient vitamin D intake. This hormone supports the normal, orderly growth of both the baby and the placenta and is vital in the life-and-death struggle against those that are evil, right smack-dab within the placenta. Surprisingly, bacteria take up residence within the placenta, so keeping harmful bacteria in check is crucial. There is a baby at risk.

“The placenta is one of the most poorly understood human organs, particularly with regard to the presence of microbes within it.” (Nuriel-Ohayon et al., 2016)

We should no longer view the placenta as a sterile environment. Quite the opposite, the placenta harbors many bacteria. Bacteria are also found in the amniotic fluid and the vascular network connecting the baby to the placenta, specifically the umbilical cord (Nuriel-Ohayon et al., 2016). This is important: bacteria must be kept in check, or there will be no baby. Enter the power of vitamin D.

Vitamin D supports many physiological activities that help the placenta mount a robust and lethal immune response against bacteria, while also exercising restraint to prevent harm to the precious little one that the placenta strives to nourish and protect. Even in a healthy pregnancy, enemies lurk in the shadows. They want to destroy “Baby.” Yes, they are that evil. However, vitamin D sufficiency can minimize this threat. So, why are so many mothers allowed to remain vitamin D deficient? Are we looking at another 25 years to pass before we see the following?

“The routine monitoring of vitamin D levels in antenatal period [period before or during pregnancy] is mandatory. Early preventative measures should be taken at the slightest suspicion of vitamin D deficiency in pregnant women, to reduce morbidity during pregnancy and lactation, as well as its subsequent impact on the fetus, the newborn and the child.” (Urrutia-Pereira and Solé, 2015)

There’s no doubt that the ideal placenta is one that is well-formed, functions properly, and adequately supports fetal growth. To achieve this, you need vitamin D on your side. You have no choice in the matter.

“Vitamin D is considered as having a major role in the synthesis and regulation of genes that are effective in the early development phase of the placenta.” (Bakacak et al., 2015)

“The placenta plays a crucial role in fetal health, and it is well known that placental pathologies, specifically vascular lesions, affect fetal growth.

“Inadequate growth in utero is not only linked to immediate morbidity and mortality risk of offspring but also lifelong risk of chronic disease.” (Gernand et al., 2013, emphasis added)

Research has revealed the crucial role that vitamin D plays in the normal development of the placenta. Additionally, research has shown that vitamin D deficiency can impair placental vascular development (Gernand et al., 2013). A baby born to a mother with vitamin D deficiency may experience growth restriction because a poorly developed placenta cannot meet their nutritional needs (Wagner and Hollis, 2018). These challenges can lead to low birth weight or preterm births, which might leave some babies unprepared for life outside the womb. Tragically, in severe cases, this can lead to long-term, serious health issues or even death.

Further, regarding fetal growth restriction:

“Maternal vitamin D deficiency has been associated with many poor birth outcomes, including fetal growth restriction. A recent Cochrane Review showed that vitamin D supplementation reduces the incidence of low birth weight … by 52%.” (Gernand et al., 2013, emphasis added)

Let me remind you—Vitamin D deficiency is common in ladies who make babies. And there may be more pregnant women with vitamin D deficiency than those with healthy levels—you should check out the statistics I’ve seen! Unfortunately, vitamin D deficiency can lead to a range of complications. However, some of this (madness) can be corrected when this vitamin, this hormone, is adequately supplied. “Vitamin D deficiency is implicated in reduced fetal growth, which may be rescued by supplementation of vitamin D.” (Murthi et al., 2016) Tragically, some of the damage may never be reversed, making prevention and early intervention essential.

Besides fetal growth restriction, an abnormal placenta can lead to preeclampsia, “a disorder involving dysregulated placental vascularization that affects up to 10% of pregnancies.” (Liu et al., 2011) Vitamin D deficiency is implicated here, as well, as one might expect. One study found, “patients with 25(OH)D levels 15 ng/mL [quite low, but common] had a 5-fold increase in the risk of preeclampsia, despite receiving prenatal vitamins.” (Mulligan et al., 2010, emphasis added) Other studies have found similar results. For example:

“In a recent study, the odds of severe preeclampsia decreased by 38% for every 10 nmol/L increase in 25(OH)D [vitamin D].” (Christensen et al., 2012)

“Almost all cross-sectional studies have reported a significant association between vitamin D deficiency and risk of pre-eclampsia.” (Tabesh et al., 2013)

“Women with vitamin D deficiency (<20 ng/ml) were more likely to have low levels of placental growth factor, which is associated with an increased risk of preeclampsia.” (Fanos et al., 2013)

I won’t go into the details of preeclampsia at this time. I need to bring this presentation to a close. However, I will take the time to tell you that you don’t want anything to do with preeclampsia. There is danger there. Stay away! Yet sadly, although it is known that vitamin D deficiency threatens the pregnancy and harms and kills babies (and placentas), we pay little attention to vitamin D during this critical period in life. And I quote:

“Vitamin D deficiency is often clinically unrecognized, however laboratory measurements are easy to perform, and treatment of vitamin D deficiency is inexpensive.” (Grundermann and von Versen-Höynck, 2011)

“Vitamin D is important to maternal health, fetal development, and postnatal life. Current prenatal care does not include the monitoring of vitamin D levels, which is an unfortunate oversight because deficiency is easily treated.” (Mulligan et al., 2010)

Before I let you go, I should tie up a few lose ends. Earlier in this article, I wrote “what is good for the baby is also good for the placenta.” Obviously, smoking is totally out of the question—very harmful to the vascular health of the placenta (Zdravkovic et al., 2005). A healthy diet, one that includes adequate amounts of “calcium, magnesium, selenium and vitamin A and C,” along with vitamin D in generous supply, will help you construct a healthy placenta (Bakacak et al., 2015). Your prenatal supplement will deliver some of the nutrients you need, but it will not provide you with enough vitamin D to make and keep you vitamin D sufficient (McCullough, 2007). And if you are taking a prenatal supplement without iodine, I will have to track you down and make you read my birth defect book. (During gestation, a baby can be damaged, sometimes irreparably damaged, when the mother is low in iodine.)

Also earlier, I wrote, “Mom, it’s up to you to become cutting edge.” By saying this, I encourage you to become aware of the issues surrounding vitamin D and pregnancy and not remain part of the problem. Year after year, I read paper after paper detailing the discoveries and conclusions of the experts, yet little change can be observed in how we address a problem that harms and destroys, namely, vitamin D deficiency. Year after year, the belief that only a small amount of vitamin D is required during pregnancy is tightly held. No sense of urgency can be seen. No change is in sight. The darkness needs to end. It can start with you. You can request a vitamin D level to see where you stand. And from there, you can insist on effective treatment, as indicated.

I will conclude with this:

“Finally, let us discuss a scenario that occurs thousands of times daily in the United States. A pregnant woman visits her obstetrician, who prescribes prenatal vitamins containing 400 IU (10µg) vitamin D. The patient and physician both assume that this supplement will fulfill all the nutritional requirements for the duration of the pregnancy. However, in the case of vitamin D, it will not even come close unless the pregnant woman has adequate sun exposure. The woman, especially if African American, and her developing fetus are at high risk of remaining vitamin D deficient during the entire pregnancy. Even if the physician were to prescribe a vitamin D supplement of 1,000 IU/d (25 µg), the mother would likely remain vitamin D deficient. As scientists and health care providers, we simply cannot accept this any longer.” (Hollis and Wagner, 2004)

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References

Bakacak M, Serin S, Ercan O, Köstü B, Avci F, Kılınç M, Kıran H, Kiran G 2015 Comparison of Vitamin D Levels in Cases with Preeclampsia, Eclampsia and Healthy Pregnant Women. International Journal of Clinical and Experimental Medicine. 8(9):16280

Christensen HT, Falkenberg T, Lamont RF, Jørgensen JS 2012 The Impact of Vitamin D on Pregnancy: A Systematic Review. ACTA Obstetrica et Gynecologica 91(2012):1357–1367

Fanos M, Vierucci F, Saggese G 2013 Vitamin D in the Prenatal Period: An Update. Journal of Pediatric and Neonatal Individualized Medicine 2(2):e020202

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Tabesh M, Salehi-Abargouei A, Tabesh M, Esmaillzadeh A 2013 Maternal Vitamin D Status and Risk of Pre-eclampsia: A Systematic Review and Meta-analysis. The Journal of Clinical Endocrinology & Metabolism. Jun 19; 98(8):3165–3173

Urrutia-Pereira M, Solé D 2015 Vitamin D Deficiency in Pregnancy and Its Impact on the Fetus, the Newborn and in Childhood. Revista Paulista de Pediatria. Mar; 33(1):104–13

Wagner CL, Hollis BW. The implications of vitamin D status during pregnancy on mother and her developing child. Frontiers in endocrinology. 2018 Aug 31;9:500.

Zdravkovic T, Genbacev O, McMaster MT, Fisher SJ 2005 The Adverse Effects of Maternal Smoking on the Human Placenta: A Review. Placenta. Apr 30; 26:S81–6

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