Babies born to mothers with high blood pressure during pregnancy have significantly lower vitamin D levels at birth, according to a 2026 cross-sectional analysis of 400 pregnancies published in Early Human Development. Gram Research analysis found that newborns in the high blood pressure group had vitamin D levels about 6 points lower than healthy pregnancies, and not a single baby in this group met the adequate vitamin D threshold. This deficit persisted even after accounting for the mother’s own vitamin D levels, suggesting pregnancy complications may impair how vitamin D transfers from mother to baby.
Researchers studied vitamin D levels in newborns whose mothers had pregnancy complications like high blood pressure, severe anemia, or gestational diabetes. They found that babies born to mothers with high blood pressure had significantly lower vitamin D levels at birth, even when accounting for the mother’s own vitamin D levels. This suggests that pregnancy complications may affect how vitamin D passes from mother to baby through the placenta. The study included 400 first-time mothers and their newborns, making it one of the largest analyses of this connection.
Key Statistics
A 2026 cross-sectional study of 400 first-time pregnancies found that babies born to mothers with pregnancy-related high blood pressure had cord blood vitamin D levels 6.14 points lower than babies from healthy pregnancies, even after adjusting for maternal vitamin D levels.
According to research reviewed by Gram, zero out of 75 babies (0%) born to mothers with pregnancy-related high blood pressure had adequate vitamin D levels at birth, compared to expected rates in healthy pregnancies.
A 2026 analysis of 400 pregnancies found that severe anemia during pregnancy was associated with a 2.93-point reduction in newborn vitamin D levels, a smaller but still significant deficit compared to healthy pregnancies.
Research published in Early Human Development in 2026 showed that gestational diabetes did not significantly affect newborn vitamin D levels, suggesting this pregnancy complication does not substantially impair vitamin D transfer from mother to baby.
The Quick Take
- What they studied: Whether pregnancy complications affect how much vitamin D babies receive before birth
- Who participated: 400 first-time pregnant women in active labor at 34 weeks or later: 75 with high blood pressure during pregnancy, 75 with severe anemia, 50 with gestational diabetes, and 200 with healthy pregnancies
- Key finding: Babies born to mothers with pregnancy-related high blood pressure had vitamin D levels about 6 points lower than healthy pregnancies, even after accounting for the mother’s vitamin D levels. Not a single baby in the high blood pressure group had adequate vitamin D at birth.
- What it means for you: If you have high blood pressure during pregnancy, your baby may need vitamin D monitoring after birth. Talk to your doctor about vitamin D supplementation during pregnancy and screening for your newborn.
The Research Details
This was a cross-sectional study, meaning researchers collected information from all participants at one point in time (at delivery). They measured vitamin D levels in cord blood (blood from the umbilical cord) from 400 first-time mothers and compared the levels across four groups: those with pregnancy-related high blood pressure, severe anemia, gestational diabetes, and healthy pregnancies.
The researchers used a statistical method called ANCOVA to compare vitamin D levels between groups while accounting for the mother’s own vitamin D levels. They also ran additional analyses that adjusted for how far along the pregnancy was and the baby’s birth weight. This approach helps isolate whether pregnancy complications themselves affect vitamin D transfer, rather than just reflecting the mother’s vitamin D status.
All participants were at least 34 weeks pregnant when they gave birth, which is considered late in pregnancy. This timing is important because most vitamin D transfer from mother to baby happens in the final weeks of pregnancy.
Understanding how pregnancy complications affect vitamin D transfer is important because vitamin D plays a critical role in bone development, immune function, and calcium absorption in newborns. If certain pregnancy conditions impair this transfer, babies may start life with a vitamin D deficit that could have long-term health implications. This research helps identify which pregnancies need closer monitoring and intervention.
This study has several strengths: a reasonably large sample size (400 participants), careful statistical adjustment for confounding factors, and clear definitions of pregnancy complications. However, it has limitations: it only measured vitamin D at one point (delivery), so we cannot determine when the deficit developed. The study also could not directly measure placental function or vitamin D transport, so while the findings suggest altered placental handling, they do not prove it. Additionally, this was a cross-sectional study rather than a randomized trial, so causation cannot be definitively established.
What the Results Show
Babies born to mothers with pregnancy-related high blood pressure had cord blood vitamin D levels approximately 6 points lower than babies from healthy pregnancies (measured on a scale where higher is better). This difference remained significant even after researchers accounted for the mother’s own vitamin D levels, suggesting the pregnancy complication itself affects vitamin D transfer. Remarkably, none of the 75 babies born to mothers with high blood pressure during pregnancy had vitamin D levels considered adequate (20 ng/mL or higher).
When researchers adjusted their analysis for how far along the pregnancy was and the baby’s birth weight, the vitamin D deficit in the high blood pressure group remained substantial, dropping from 6.14 points to 4.85 points. This persistence suggests the effect is real and not simply explained by premature birth or smaller babies.
Severe anemia during pregnancy showed a smaller but still significant vitamin D deficit in newborns, about 2.93 points lower than healthy pregnancies. This deficit also remained after adjusting for other factors, though it was less pronounced than in the high blood pressure group.
Gestational diabetes (high blood sugar during pregnancy) did not show a significant vitamin D deficit in newborns compared to healthy pregnancies, suggesting this complication does not substantially affect vitamin D transfer from mother to baby.
The study found that maternal vitamin D levels were an important predictor of cord blood vitamin D levels, as expected. However, the fact that pregnancy complications created additional deficits beyond what the mother’s vitamin D status would predict suggests these conditions specifically interfere with the placenta’s ability to transfer vitamin D. The researchers noted that the complete absence of adequate vitamin D in babies born to mothers with pregnancy-related high blood pressure (0 out of 75 babies) is particularly striking and warrants clinical attention.
Previous research has shown that vitamin D deficiency is common in pregnancy, especially in certain populations. This study adds important new information by demonstrating that specific pregnancy complications, particularly high blood pressure, may further compromise vitamin D transfer to the fetus. The finding that gestational diabetes does not significantly affect vitamin D transfer contradicts some earlier smaller studies and suggests this complication may not be a primary risk factor for neonatal vitamin D deficiency.
This study has several important limitations. First, it measured vitamin D only at delivery, so researchers cannot determine when the deficit developed or whether it worsens as pregnancy progresses. Second, the study did not directly measure placental function or vitamin D transport mechanisms, so while the findings suggest altered placental handling, they cannot prove it. Third, this is a cross-sectional study, which means it shows associations but cannot establish that pregnancy complications cause vitamin D deficiency. Fourth, the study was conducted at a single hospital, so results may not apply to all populations. Finally, the study did not follow babies after birth, so long-term health effects of these vitamin D deficits are unknown.
The Bottom Line
Pregnant women, especially those with high blood pressure during pregnancy, should discuss vitamin D supplementation with their healthcare provider. Gram Research analysis suggests babies born to mothers with pregnancy-related high blood pressure should be screened for vitamin D deficiency after birth. Healthcare providers may consider more aggressive vitamin D supplementation during pregnancy for women with hypertensive disorders. These recommendations have moderate confidence because the study shows association but cannot prove causation.
Pregnant women with high blood pressure during pregnancy should prioritize vitamin D monitoring and supplementation. Women with severe anemia during pregnancy may also benefit from vitamin D assessment. Obstetricians and pediatricians should be aware that babies born to mothers with pregnancy-related high blood pressure are at high risk for vitamin D deficiency. Women with gestational diabetes do not appear to need additional vitamin D monitoring based on this research.
Vitamin D deficiency effects develop gradually. Babies born with low vitamin D may not show symptoms immediately, but deficiency can affect bone development and immune function over months and years. Supplementation should begin as soon as deficiency is identified, with benefits appearing over weeks to months.
Frequently Asked Questions
Does high blood pressure during pregnancy affect my baby’s vitamin D levels?
Yes. A 2026 study of 400 pregnancies found babies born to mothers with pregnancy-related high blood pressure had significantly lower vitamin D at birth, with none meeting adequate levels. This suggests the condition impairs vitamin D transfer from mother to baby.
Should I take extra vitamin D if I have gestational diabetes?
Based on current research, gestational diabetes does not appear to affect vitamin D transfer to your baby. However, discuss vitamin D supplementation with your doctor, as individual needs vary based on your baseline vitamin D status.
What vitamin D level should my newborn have?
Adequate vitamin D at birth is generally considered 20 ng/mL or higher. A 2026 study found that babies born to mothers with pregnancy-related high blood pressure had levels below this threshold, highlighting the importance of newborn screening and supplementation.
Can vitamin D supplements during pregnancy prevent deficiency in my baby?
Prenatal vitamin D supplementation helps, but pregnancy complications like high blood pressure may still reduce transfer to your baby. Discuss appropriate supplementation doses with your doctor, especially if you have pregnancy complications.
Does severe anemia during pregnancy affect my baby’s vitamin D?
Yes, but less severely than high blood pressure. A 2026 study found severe anemia was associated with a smaller vitamin D deficit in newborns. Discuss vitamin D monitoring with your healthcare provider if you have anemia during pregnancy.
Want to Apply This Research?
- If pregnant, track your vitamin D supplementation dose daily and log any pregnancy complications (high blood pressure readings, anemia symptoms). After birth, log your baby’s vitamin D screening results and supplementation doses.
- Start taking a prenatal vitamin with vitamin D (typically 600 to 1000 IU daily, or as recommended by your doctor). If you have pregnancy-related high blood pressure, ask your doctor about higher-dose vitamin D supplementation. After birth, ensure your baby receives vitamin D screening and supplementation as recommended.
- Track maternal vitamin D levels at each prenatal visit if available. After birth, monitor your baby’s vitamin D supplementation adherence and request follow-up testing at 4 to 8 weeks of age, especially if born to a mother with pregnancy-related high blood pressure.
This article summarizes research findings and should not replace professional medical advice. Vitamin D supplementation during pregnancy and newborn vitamin D screening should be discussed with your obstetrician or healthcare provider, who can assess your individual risk factors and recommend appropriate treatment. If you have been diagnosed with a pregnancy complication such as high blood pressure, severe anemia, or gestational diabetes, work closely with your healthcare team on all aspects of your care, including vitamin D status. This research shows association but does not establish causation, and individual results may vary.
This research translation is published by Gram Research, the science division of Gram, an AI-powered nutrition tracking app.