Lactation, Pregnancy
Conditions
Keywords
vitamin D, Africa
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.
Interventions
OTHEROral 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.
Sponsors
Medical Research Council
Study design
Allocation
NON_RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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) |
Outcome results
None listed