Vitamin D Half-life in Pregnancy and Lactation

Not Applicable

Completed

• Conditions: Pregnancy; Lactation
• Interventions: Other: Oral dose of stable isotope labeled 25(OH)D3

• Registration Number: NCT02621827
• Lead Sponsor: Medical Research Council

Brief Summary

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.

Detailed Description

Not available

Study Timeline

• Study Start: 2011-11
• Primary Completion: 2012-10
• Study Completion: 2013-05
• Study First Submitted: 2015-11-27
• Status Verified: 2015-12
• Study First Submitted QC: 2015-12-01
• Last Update Submitted: 2015-12-01
• Study First Posted: 2015-12-04
• Last Update Posted: 2015-12-04

Recruitment & Eligibility

• Status: COMPLETED
• Sex: Female
• Target Recruitment: 49

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 & Design

• Study Type: INTERVENTIONAL
• Study Design: SINGLE_GROUP

Arm && Interventions

Group	Intervention	Description
Pregnant/Lactating	Oral dose of stable isotope labeled 25(OH)D3	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.
Non-pregnant, non-lactating (NPNL)	Oral dose of stable isotope labeled 25(OH)D3	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.

Primary Outcome Measures

Name	Time	Method
Plasma concentration of stable isotope labeled 25(OH)D3	Samples collected on day 6, 9, 21, 24, 27 and 30 post-dose	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

Secondary Outcome Measures

Name	Time	Method
Plasma concentration of vitamin D metabolites and related calciotropic hormones	Fasting plasma samples collected at baseline and 21 days post-dose	Analytes: 25(OH)D3, 24,25(OH)2D3, 1,25(OH)2D, vitamin D binding protein, parathyroid hormone, albumin, ionised calcium, phosphate
Urinary concentration of calcium, phosphate, creatinine and cyclic adenosine monophosphate (cAMP)	Samples collected at baseline and 21 days post-dose	2-hour fasting urine collection
Weighed dietary intake	2 days within 30 days of dose	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)