MedPath

Impact of Maternal Body Weight on Vitamin D Status During Pregnancy

Not Applicable
Completed
Conditions
Vitamin D Deficiency
Obesity
Interventions
Dietary Supplement: Pregnancy multi-vitamin (including 10μg vitamin D3)
Dietary Supplement: 10μg vitamin D3
Dietary Supplement: 0μg vitamin D (placebo)
Registration Number
NCT02713009
Lead Sponsor
University of Ulster
Brief Summary

Research shows high levels of vitamin D deficiency in pregnant women in Northern Ireland. Body composition is a determinant of vitamin D status. Vitamin D is a fat soluble vitamin and therefore may be hidden within the adipose/fat tissue in overweight/obese individuals. All pregnant and breastfeeding women are advised to take a daily supplement containing 10μg vitamin D. The investigators hypothesise that overweight/ obese pregnant women have a lower vitamin D status than their leaner counterparts at the start of pregnancy and may need a higher daily supplementation to achieve a sufficient status.

The investigators propose a randomised supplementation study where pregnant women (n 240) from the Western Health and Social Care Trust Area will be invited to take part.

Inclusion criteria: pregnant women first trimester, without current pregnancy related complications, singleton pregnancy, aged ≥18 years, with Body Mass Index (BMI) \> 18.5kg /m².

Participants will be randomised to receive either 0μg (placebo) plus a multivitamin or 10μg vitamin D plus a multivitamin from 12 weeks gestation until delivery. The multivitamin already contains 10μg vitamin D; Therefore participants will be randomised to receive a total of 10μg or 20μg vitamin D.

Blood samples (20mls) will be taken at 12, 28 and 36 weeks gestation. A sample of blood will be taken from the cord after delivery. Vitamin D status is the main outcome measurement. All blood samples will be analysed for vitamin D and other associated metabolites. Data will be collected on health and lifestyle, supplementation use and food intake. Body composition measurements will be recorded at each appointment and infant anthropometric measurements will be taken from the maternal notes after delivery. Findings from this research will be used to inform nutrition policy on appropriate vitamin D supplementation levels in pregnancy which may be dependent upon pre pregnancy BMI.

Detailed Description

Not available

Recruitment & Eligibility

Status
COMPLETED
Sex
Female
Target Recruitment
240
Inclusion Criteria
  • Pregnant women
  • Age ≥18years
  • BMI >18.5 kg/m²
  • Without current pregnancy related complications
  • At least 12 weeks gestation
  • Have a singleton pregnancy (as confirmed at first scan)
  • Pregnant women who are currently taking vitamin D and have had a sun holiday will be included in this study. All participants will agree to discontinue any current supplementation and will be provided with a multivitamin for the duration of pregnancy.
Exclusion Criteria
  • Aged <18 years
  • Pregnancy BMI <18.5kg/m²
  • Participants with multiple pregnancy
  • Participants currently involved in another research study
  • Participants with a history of gastrointestinal, hepatic, renal, vascular or haematological disorders.
  • Participants who have had in vitro fertilisation (IVF) treatment
  • Participants with a history of NTD affected pregnancies
  • Pregnant women with active thyroid disease (e.g., Graves, Hashimoto or thyroiditis)
  • Planned home births

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Treatment 110μg vitamin D3Pregnancy multivitamin + vitamin D daily from \~Week 12 gestation until delivery
Treatment 20μg vitamin D (placebo)Pregnancy multivitamin + placebo daily from \~Week 12 gestation until delivery
Treatment 1Pregnancy multi-vitamin (including 10μg vitamin D3)Pregnancy multivitamin + vitamin D daily from \~Week 12 gestation until delivery
Treatment 2Pregnancy multi-vitamin (including 10μg vitamin D3)Pregnancy multivitamin + placebo daily from \~Week 12 gestation until delivery
Primary Outcome Measures
NameTimeMethod
Change in Vitamin D (25-hydroxyvitamin D) statusBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

Serum Vitamin D status (Week 12, 28 + 36 gestation) \& cord serum Vitamin D status (delivery)

Secondary Outcome Measures
NameTimeMethod
Gestational weight gainBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation)
Change in inflammation statusBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

Plasma inflammation status (Week 12, 28 + 36 gestation) \& cord plasma inflammation status (delivery)

Change in bone turnover markersBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

Plasma bone turnover markers (Week 12, 28 + 36 gestation) \& cord plasma bone turnover markers (delivery)

Change in Vitamin D related measuresBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

Blood Vitamin D related status (Week 12, 28 + 36 gestation) \& cord Vitamin D related status (delivery)

Transferrin saturationBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

Clinical chemistry analyser

Soluble transferrin receptorBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

ELISA

Dietary intakeWeek 28 gestation

Food diary with food frequency questionnaire

Foetal growth chart measurementBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Plasma ferritinBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

Clinical chemistry analyser

GeneticsBaseline (Week 12 gestation)

e.g. CYP2R1, CYP27B1, CYP24A1

HaemoglobinBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

As part of full blood count

Iron statusBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

Serum, clinical chemistry analyser

HepcidionBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

ELISA

Methylation analysisBaseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

Iron and vitamin D related genes

Trial Locations

Locations (1)

Western Health and Social Care Trust, Altnagelvin

🇬🇧

Londonderry, Co.Londonderry, United Kingdom

© Copyright 2025. All Rights Reserved by MedPath