Vitamin D Half-life in Pregnancy and Lactation

This study measures the plasma half-life of 25-hydroxyvitamin D3 (25(OH)D3) in non-pregnant-non-lactating women, pregnant women at 30 wk gestational age and at 3 months post-partum in women who are exclusively breast-feeding.

Study Overview

• Status: Completed
• Conditions: Pregnancy; Lactation
• Intervention / Treatment: Other: Oral dose of stable isotope labeled 25(OH)D3

• Study Type: Interventional
• Enrollment (Actual): 49
• Phase: Not Applicable

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 45 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

All participants:

• Currently resident in West Kiang and planning to stay for the next 5 months
• Aged between 18 and 45 y

Pregnancy:

• > 20 wk < 30 wk pregnant (gestational age assessment by ultrasound)
• Singleton fetus

Lactation:

• Breast feeding

Exclusion Criteria:

All participants:

• Severe anaemia (haemoglobin < 7 g/dL) (as per ENID protocol)
• Known sickle cell anaemia
• Known to be asthmatic or allergic to peanuts (already excluded from ENID)
• Known history of liver, kidney, gut or malabsorption problems
• Other chronic condition
• On prescription medication
• Taking vitamin D supplements (> 200 IU/d)
• Broken bone in last 3 y
• Recent infection or illness (2 weeks prior to the start of a study period)
• Reported onset of menopause (already excluded from ENID)
• Malaria parasitemia (prior to study period)
• Unable to consent

Pregnant:

• Pregnancy-related complications or on discretion of mid-wife
• Known HIV positive

Lactation:

• Health problem of mother or infant that may affect feeding practices

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Non-pregnant, non-lactating (NPNL); NPNL women are age and parity matched to pregnant women. Each NPNL women is studied twice, approximately 3 months apart. At each study period the participant receives (as the intervention) a single oral dose of stable isotope labeled 25(OH)D3.	Other: Oral dose of stable isotope labeled 25(OH)D3; At each measurement, women are given an oral dose of stable isotope labelled 25(OH)D3. Blood and urine samples are collected at baseline and on day 21 post-dose. Additional blood samples are collected post-dose on days 6,9,24,27 and 30.
Experimental: Pregnant/Lactating; Pregnant women receive (as the intervention) a single oral dose of stable isotope labeled 25(OH)D3. The same women are followed-up in lactation to repeat the same protocol.	Other: Oral dose of stable isotope labeled 25(OH)D3; At each measurement, women are given an oral dose of stable isotope labelled 25(OH)D3. Blood and urine samples are collected at baseline and on day 21 post-dose. Additional blood samples are collected post-dose on days 6,9,24,27 and 30.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma concentration of stable isotope labeled 25(OH)D3	The plasma half-life of 25(OH)D3 is calculated from the slope (k) of the disappearance of the stable isotope labeled 25(OH)D3 against time using the equation half-life=0.693/k	Samples collected on day 6, 9, 21, 24, 27 and 30 post-dose

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma concentration of vitamin D metabolites and related calciotropic hormones	Analytes: 25(OH)D3, 24,25(OH)2D3, 1,25(OH)2D, vitamin D binding protein, parathyroid hormone, albumin, ionised calcium, phosphate	Fasting plasma samples collected at baseline and 21 days post-dose
Urinary concentration of calcium, phosphate, creatinine and cyclic adenosine monophosphate (cAMP)	2-hour fasting urine collection	Samples collected at baseline and 21 days post-dose
Weighed dietary intake	Dietary nutrient intakes assessed by 2-day weighed food diary and nutrient intakes calculated using DINO (diet in nutrients out) analysis programme (Fitt et al, 2015)	2 days within 30 days of dose

Collaborators and Investigators

• Sponsor: Medical Research Council

Study record dates

Study Major Dates

• Study Start: November 1, 2011
• Primary Completion (Actual): October 1, 2012
• Study Completion (Actual): May 1, 2013

Study Registration Dates

• First Submitted: November 27, 2015
• First Submitted That Met QC Criteria: December 1, 2015
• First Posted (Estimate): December 4, 2015

Study Record Updates

• Last Update Posted (Estimate): December 4, 2015
• Last Update Submitted That Met QC Criteria: December 1, 2015
• Last Verified: December 1, 2015

More Information

Terms related to this study

• Keywords: Africa; vitamin D
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Micronutrients; Vitamins; Bone Density Conservation Agents; Calcifediol
• Other Study ID Numbers: MRC SCC1229