Clinical trial NCT02713009: Impact of Maternal Body Weight on Vitamin D Status During Pregnancy
Official title: Investigation of the Impact of Maternal Body Weight on Vitamin D Status During Pregnancy: a Randomised Supplementation Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Vitamin D Deficiency
Keywords: Maternal body weight
Vitamin D
Pregnancy
Lead sponsor: University of Ulster
Sponsor class: OTHER
Collaborators: name: Western Health and Social Care Trust
First posted: 2016-03-18
Enrollment: 240
Sex: FEMALE
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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.


Eligibility criteria: 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

Primary outcomes:
measure: Change in Vitamin D (25-hydroxyvitamin D) status
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Secondary outcomes:
measure: Gestational weight gain
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation)
measure: Change in inflammation status
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
measure: Change in bone turnover markers
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
measure: Genetics
timeFrame: Baseline (Week 12 gestation)
measure: Dietary intake
timeFrame: Week 28 gestation
measure: Foetal growth chart measurement
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
measure: Change in Vitamin D related measures
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
measure: Haemoglobin
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
measure: Plasma ferritin
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
measure: Transferrin saturation
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
measure: Iron status
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
measure: Soluble transferrin receptor
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
measure: Hepcidion
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
measure: Methylation analysis
timeFrame: Baseline (Week 12 gestation), Mid-point (Week 28 gestation) & End of pregnancy (Week 36 gestation + Delivery)
Other outcomes:
Locations:
city: Londonderry
country: United Kingdom
facility: Western Health and Social Care Trust, Altnagelvin
state: Co.Londonderry
Study officials:
References:
citation: 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.