Impact of Maternal Body Weight on Vitamin D Status During Pregnancy (MO-VITD)

Investigation of the Impact of Maternal Body Weight on Vitamin D Status During Pregnancy: a Randomised Supplementation Study

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.

Study Overview

• Status: Completed
• Conditions: Obesity; Vitamin D Deficiency
• Intervention / Treatment: Dietary supplement: Pregnancy multi-vitamin (including 10μg vitamin D3); Dietary supplement: 10μg vitamin D3; Dietary supplement: 0μg vitamin D (placebo)

• Study Type: Interventional
• Enrollment (Actual): 240
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Mary T McCann; Phone Number: +4428 70 123969; Email: mt.mccann@ulster.ac.uk

Study Locations

• United Kingdom
  • Co.Londonderry
    • Londonderry, Co.Londonderry, United Kingdom
      • Western Health and Social Care Trust, Altnagelvin

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Female

Description

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 Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Treatment 1; Pregnancy multivitamin + vitamin D daily from ~Week 12 gestation until delivery	Dietary supplement: Pregnancy multi-vitamin (including 10μg vitamin D3); Dietary supplement: 10μg vitamin D3
Placebo Comparator: Treatment 2; Pregnancy multivitamin + placebo daily from ~Week 12 gestation until delivery	Dietary supplement: Pregnancy multi-vitamin (including 10μg vitamin D3); Dietary supplement: 0μg vitamin D (placebo)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Vitamin D (25-hydroxyvitamin D) status	Serum Vitamin D status (Week 12, 28 + 36 gestation) & cord serum Vitamin D status (delivery)	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gestational weight gain		Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation)
Change in inflammation status	Plasma inflammation status (Week 12, 28 + 36 gestation) & cord plasma inflammation status (delivery)	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Change in bone turnover markers	Plasma bone turnover markers (Week 12, 28 + 36 gestation) & cord plasma bone turnover markers (delivery)	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Genetics	e.g. CYP2R1, CYP27B1, CYP24A1	Baseline (Week 12 gestation)
Dietary intake	Food diary with food frequency questionnaire	Week 28 gestation
Foetal growth chart measurement		Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Change in Vitamin D related measures	Blood Vitamin D related status (Week 12, 28 + 36 gestation) & cord Vitamin D related status (delivery)	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Haemoglobin	As part of full blood count	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Plasma ferritin	Clinical chemistry analyser	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Transferrin saturation	Clinical chemistry analyser	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Iron status	Serum, clinical chemistry analyser	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Soluble transferrin receptor	ELISA	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Hepcidion	ELISA	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Methylation analysis	Iron and vitamin D related genes	Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)

Collaborators and Investigators

• Sponsor: University of Ulster
• Collaborators: Western Health and Social Care Trust

Publications and helpful links

General Publications

• Alhomaid RM, Mulhern MS, Strain J, Laird E, Healy M, Parker MJ, McCann MT. Maternal obesity and baseline vitamin D insufficiency alter the response to vitamin D supplementation: a double-blind, randomized trial in pregnant women. Am J Clin Nutr. 2021 Sep 1;114(3):1208-1218. doi: 10.1093/ajcn/nqab112.

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2015
• Primary Completion (Actual): March 1, 2018
• Study Completion (Actual): March 1, 2018

Study Registration Dates

• First Submitted: January 14, 2016
• First Submitted That Met QC Criteria: March 14, 2016
• First Posted (Estimate): March 18, 2016

Study Record Updates

• Last Update Posted (Estimate): March 3, 2023
• Last Update Submitted That Met QC Criteria: February 28, 2023
• Last Verified: February 1, 2023

More Information

Terms related to this study

• Keywords: Vitamin D; Pregnancy; Maternal body weight
• Additional Relevant MeSH Terms: Nutrition Disorders; Avitaminosis; Deficiency Diseases; Malnutrition; Vitamin D Deficiency; Body Weight; Physiological Effects of Drugs; Micronutrients; Bone Density Conservation Agents; Calcium-Regulating Hormones and Agents; Vitamin D; Cholecalciferol; Vitamins; Ergocalciferols
• Other Study ID Numbers: REC 15/NI/0068