Pediatric Academic Societies Annual Meeting
VANCOUVER, British Columbia Mothers who took high
doses of vitamin D during pregnancy experienced lower preterm labor, preterm
birth and infection rates compared with mothers who did not, according to a
speaker at the 2010 Pediatric Academic Societies Annual Meeting.
In the past, some worried that vitamin D caused birth
defects, said Carol L. Wagner, MD, of the Medical University of South
Carolina in Charleston. However, recent research supports the importance of
vitamin D in promoting bone health and immune function for both mothers and
Wagner and colleagues conducted a randomized controlled
trial to determine the optimal dose of vitamin D supplements for pregnant women
without causing harm. They randomly assigned 494 pregnant women at 12- to 16-
weeks gestation to 400 IU (control group; n=111), 2,000 IU (n=122) or 4,000 IU
(m=117) of vitamin D per day until delivery; 350 women continued to delivery.
After performing logistic regression analyses to
determine the effects of vitamin D on preeclampsia, gestational diabetes,
infections and preterm labor and birth, the researchers determined that women
who took the highest of these three daily doses had half the risk for
comorbidities than the control group (RR=0.50; 95% CI, 0.27-0.95;
No adverse events related to vitamin D dosing were
found in any of the three arms of the study, Wagner said, noting that
more detailed safety data will also be presented at the meeting.
Based on these findings the researchers recommended a
daily regimen of 4,000 IU a day for all pregnant women, an increase from
current recommendations that state that infants should receive 400 IU a day,
children, 200 IU and adults older than 70 years, 600 IU.
Diet doesnt provide enough vitamin D, and we
dont go in the sun as much as we need, Wagner said.
The researchers observed several other significant
effects among the study groups attributable to vitamin D supplements:
- Mean 25-hydroxyvitamin D (25(OH)D) were significantly
different between the control group and each of the groups that received
vitamin supplements at delivery and one month before (P<.0001).
- Serum 25(OH)D levels had a direct influence on
calcitriol (1,25(OH)2D) levels throughout pregnancy (
P<.0001) with 40 ng per mL of 25(OH)D for maximum calcitriol
- Rates of pre-term labor, pre-term birth, and infection
were inversely related to 25(OH)D levels and were lowest in the 4,000 IU group
(P<.0001), after adjusting for race.
- In women without comorbidities 25(OH)D levels were
33.4 ng per mL vs. 39.0 ng per mL in those women without (P<.008).
Additionaly, neonatal serum 25(OH)D levels were
significantly correlated with maternal 25(OH)D levels overall, a month before
delivery and at delivery, according to Wagner.
On average, babies born to the control group had 18.2 ng
serum 25(OH)D per mL, compared with 22.8 among babies born to mothers who took
2,000 IU daily supplements and 26.5 among babies born to the 4,000-IU women.
by Nicole Blazek
For more information:
- Wagner CL. #1665.6. Presented at: 2010 Pediatric Academic Societies
Annual Meeting; May 1-4, 2010; Vancouver, British Columbia.
EndocrineToday.com on Twitter.