Effects of Vitamin D on Health Promotion During Pregnancy and Its Impact on Prematurity-Related Outcome

Condition(s) studied

Investigational drug(s) / intervention(s)

Exposure: Maternal vitamin D levels during pregnancy (serum 25-hydroxyvitamin D levels)

Study summary

The VitDTracking study focuses on the relevance of maternal vitamin D levels and their association with prematurity, aiming to improve maternal and child health outcomes, particularly by reducing avoidable preterm births. In Portugal, vitamin D levels during pregnancy have never been studied. Epidemiological data from other countries reveal a high prevalence of vitamin D deficiency/insufficiency, especially in pregnant women.

The hypovitaminoses prevalence remains high even with a supplementation dosage of 400 to 600 IU/day during pregnancy (dosage used in Portugal), which is considered as a suboptimal dose. This phenomenon is associated with adverse maternal and child outcomes, such as intrauterine growth restriction, preeclampsia, cholestasis, hypertension, and gestational diabetes as major causes of prematurity.

Additionally, the Portuguese population has a higher prevalence of genome alterations that confer a lower capacity to produce vitamin D from sunlight exposure. These genetic characteristics are present in about 19% of the population, representing a prevalence four times higher than the European average (19% versus 4.75%), leading to a higher predisposition to vitamin D deficiency.

Eligibility

Primary outcome measure(s)

• Differences in the rate of Prematurity with different maternal Vitamin D levels — Blood samples will be taken from pregnant women up to the 13th week of pregnancy and then at the second collection point up to 48 hours after the birth (after participant enrollment; two collection points)
  Prematurity Rate in percentage
• Differences in Birth Weight with different maternal Vitamin D levels — Blood samples will be taken from pregnant women up to the 13th week of pregnancy and then at the second collection point up to 48 hours after the birth (after participant enrollment; two collection points)
  Birth Weight in grams
• Differences in Apgar Scores with different maternal Vitamin D levels — Blood samples will be taken from pregnant women up to the 13th week of pregnancy and then at the second collection point up to 48 hours after the birth (after participant enrollment; two collection points)
  Apgar Scores in Scale (\<7 or ≥7)
• Differences in the number of admissions to the Neonatal Intensive Care Unit with different maternal Vitamin D levels — Blood samples will be taken from pregnant women up to the 13th week of pregnancy and then at the second collection point up to 48 hours after the birth (after participant enrollment; two collection points)
  Number of admissions to the Neonatal Intensive Care Unit in percentage
• Differences in the Neonatal Morbidity rate with different maternal Vitamin D levels — Blood samples will be taken from pregnant women up to the 13th week of pregnancy and then at the second collection point up to 48 hours after the birth (after participant enrollment; two collection points)
  Neonatal Morbidity rate in percentage
• Differences in the Neonatal Mortality rate with different maternal Vitamin D levels — Blood samples will be taken from pregnant women up to the 13th week of pregnancy and then at the second collection point up to 48 hours after the birth (after participant enrollment; two collection points)
  Neonatal Mortality rate in percentage
• Differences in the number of Neonatal Infections with different maternal Vitamin D levels — Blood samples will be taken from pregnant women up to the 13th week of pregnancy and then at the second collection point up to 48 hours after the birth (after participant enrollment; two collection points)
  Number of Neonatal Infections in percentage
• Differences in the Number of Congenital Malformation diagnoses with different maternal vitamin D levels — Blood samples will be taken from pregnant women up to the 13th week of pregnancy and then at the second collection point up to 48 hours after the birth (after participant enrollment; two collection points)
  Number of Congenital Malformation diagnoses in percentage
• Differences in the presence of vitamin D-related polymorphisms with different maternal levels of vitamin D — Saliva samples from pregnant women will be collected during admission to the hospital or up to 48 hours after delivery (after participant enrollment; single collection point)
  Differences will be assessed following the defined outcome indicators related to prematurity

Trial sites (3)

More University of Évora trials in Portugal

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