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.

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Key information

Conditions

Pregnancy Behavior Breast Feeding Feeding Behavior Lactation

Age range

18 year–45 year

Sex eligibility

Female

Study type

Interventional

Phase

Not applicable

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Oral dose of stable isotope labeled 25(OH)D3

Other

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.

Primary outcomes

Plasma concentration of stable isotope labeled 25(OH)D3

Time frame: 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 outcomes

Plasma concentration of vitamin D metabolites and related calciotropic hormones

Time frame: 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)

Time frame: Samples collected at baseline and 21 days post-dose

2-hour fasting urine collection
Weighed dietary intake

Time frame: 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)

Sponsors and collaborators

Lead sponsor

Medical Research Council

Other Gov

Registry information

Important dates

Study start: 2011
Primary completion: 2012
Study completion: 2013
First posted: Dec 4, 2015
Registry last updated: Dec 4, 2015

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.

Completed