Vitamin D Half-life in Pregnancy and Lactation
Studieoversigt
Status
Status
Betingelser
Betingelser
Intervention / Behandling
Intervention / Behandling
Undersøgelsestype
Undersøgelsestype
Tilmelding (Faktiske)
Tilmelding
Fase
Fase
- Ikke anvendelig
Deltagelseskriterier
Berettigelseskriterier
Berettigelseskriterier
Aldre berettiget til at studere
Tager imod sunde frivillige
Køn, der er berettiget til at studere
Beskrivelse
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
Studieplan
Hvordan er undersøgelsen tilrettelagt?
Design detaljer
- Primært formål: Grundvidenskab
- Tildeling: Ikke-randomiseret
- Interventionel model: Enkelt gruppeopgave
- Maskning: Ingen (Åben etiket)
Antal våben
Våben og indgreb
Deltagergruppe / ArmDeltagergruppe / Arm |
Intervention / BehandlingIntervention / Behandling |
|---|---|
|
Eksperimentel: 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. |
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.
|
|
Eksperimentel: 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.
|
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.
|
Hvad måler undersøgelsen?
Primære resultatmål
Primære resultatmål
Resultatmål |
Foranstaltningsbeskrivelse |
Tidsramme |
|---|---|---|
|
Plasma concentration of stable isotope labeled 25(OH)D3
Tidsramme: 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
|
Samples collected on day 6, 9, 21, 24, 27 and 30 post-dose
|
Sekundære resultatmål
Sekundære resultatmål
Resultatmål |
Foranstaltningsbeskrivelse |
Tidsramme |
|---|---|---|
|
Plasma concentration of vitamin D metabolites and related calciotropic hormones
Tidsramme: 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
|
Fasting plasma samples collected at baseline and 21 days post-dose
|
|
Urinary concentration of calcium, phosphate, creatinine and cyclic adenosine monophosphate (cAMP)
Tidsramme: Samples collected at baseline and 21 days post-dose
|
2-hour fasting urine collection
|
Samples collected at baseline and 21 days post-dose
|
|
Weighed dietary intake
Tidsramme: 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)
|
2 days within 30 days of dose
|
Samarbejdspartnere og efterforskere
Sponsor
Sponsor
Datoer for undersøgelser
Studer store datoer
Studiestart
Studiestart
Primær færdiggørelse (Faktiske)
Primær færdiggørelse
Studieafslutning (Faktiske)
Studieafslutning
Datoer for studieregistrering
Først indsendt
Først indsendt
Først indsendt, der opfyldte QC-kriterier
Først indsendt, der opfyldte QC-kriterier
Først opslået (Skøn)
Først opslået
Opdateringer af undersøgelsesjournaler
Sidste opdatering sendt (Skøn)
Sidste opdatering sendt
Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier
Sidste opdatering indsendt, der opfyldte kvalitetskontrolkriterier
Sidst verificeret
Sidst verificeret
Mere information
Begreber relateret til denne undersøgelse
Yderligere relevante MeSH-vilkår
Andre undersøgelses-id-numre
Andre undersøgelses-id-numre
- MRC SCC1229
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