AsthmaPhase 1ABCvitaminDNCT00856947
Vitamin D Supplementation During Pregnancy for Prevention of Asthma in Childhood
A Phase 1 study testing Cholecalciferol D3 in people with Asthma, run by Copenhagen Studies on Asthma in Childhood at 2 sites in Denmark.
Trial summary
The aim of this study is to prevent asthma symptoms (recurrent wheeze) in childhood by supplementation with high dose vitamin D to the mother during pregnancy. Participants are mothers and children of the ABC (Asthma Begins in Childhood) cohort. Read more about this study
- Who is it for?
- Ages 18 years and older, women onlyHealthy volunteers can take part
- Conditions the study is for
- Asthma
- What is being tested?
- Cholecalciferol D3
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 600 participants
- Where
- 2 sitesDenmark
- Study dates
- Mar 2009to Jul 2027
- Phase
- Phase 1
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- Women only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- Mother:
- Pregnant in week 22-26 of gestation
- Participating in the ABC-cohort
- Living in Sealand, Denmark
- Fluent in Danish
- Willing to let the child participate in the study
Who cannot join
- Mother:
- Intake of more than 400 IU of vitamin D during the last 6 months
- Endocrinological disease such as calcium metabolic disorder, parathyroid disorder, thyroid disorder or Diabetes type 1
- Tuberculosis
- Sarcoidosis
- In need of diuretics or heart medication including calcium channel blockers
Trial locations and contacts
2 sites in 1 country.
Denmark2 sites
Copenhagen University Hospital of Copenhagen
Gentofte Municipality, Gentofte, 2820
Næstved Hospital, Pediatric Department
Næstved, Næstved, 4700
About this study
Official title: Vitamin D Supplementation During Pregnancy for Prevention of Asthma in Childhood: An Interventional Trial in the ABC (Asthma Begins in Childhood) Cohort
The aim of this study is to prevent asthma symptoms (recurrent wheeze) in childhood by supplementation with high dose vitamin D to the mother during pregnancy. Participants are mothers and children of the ABC (Asthma Begins in Childhood) cohort. Mothers are recruited during pregnancy and receive daily supplement with 2400 IU of Vitamin D3 or placebo from week 24 og gestation to 1 week after delivery. In addition all mothers are advised to take the recommended dose of 400 IU vitamin D daily. The mothers in ABC also participate in an interventional trial with fish oil supplementation, and the vitamin D randomization is stratified by fish oil treatment group. The child is followed with acute and planned vits at the research unit, and wheeze is diagnosed according to predefined algorithms.
- Conditions
- Asthma
- Being tested
- Cholecalciferol D3, Placebo tablet
- Keywords
- wheeze, infections, allergy, eczema, vitamin D
- Medical subject headings
- Asthma, Respiratory Sounds, Infections, Hypersensitivity, Eczema
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Cholecalciferol D3Dietary supplement
Also called Vitamin D from Camette, Denmark
2 tablets of 1200 IU daily from week 24 of gestation to 1 week after delivery
Placebo tabletOther
Also called Placebo tablets from Camette, Denmark
2 tablets containing no active substance
| Study group | Role | What they receive |
|---|---|---|
| Vitamin D | Active comparator | Dietary supplement: 2400 IU Vitamin D3 (2 tablets of 1200 IU) from week 24 of gestation to 1 week after delivery Receives: Dietary Supplement: Cholecalciferol D3 |
| Placebo | Placebo comparator | Placebo: 2 placebo tablets with no active substance, identical to the active tablets, from week 24 of gestation to 1 week after delivery Receives: Other: Placebo tablet |
What is being measured
The primary outcome is the main question the study is designed to answer.
Persistent wheeze
Age at onset of persistent wheeze diagnosed according to predefined algorithm of recurrent troublesome lung symptoms, response to treatment and relapse after withdrawal of treatment
Measured: 0 to 3 years of age
Secondary outcomes (12)
Infections
Main analysis:
- Number of lower respiratory tract infections registered in daily diaries
Secondary analyses:
- Acute otitis media
- Number of upper respiratory tract infections
- Number of other infections
- Total number of infections
Measured: 0 to 3 years of age
Allergic sensitization
Allergic sensitization at 6 and/or 18 months assessed by skin prick test and specific IgE in blood
Measured: 6 and 18 months of age
Eczema
Age at onset of eczema diagnosed prospectively by research doctors according to predefined algorithm based upon Hanifin and Rajka criteria
Measured: 0 to 3 years of age
Mothers levels of 25-OH-Vitamin D, PTH, Calcium, alkaline phosphatase
Measured: 1 week after delivery
Growth
Measured: 0 to 3 years of age
Asthma exacerbations
Age at onset of severe asthma exacerbation diagnosed by predefined criteria of acute severe asthma requiring oral/high dose inhaled steroids or acute hospital contact
Measured: 0 to 3 years of age
Neurological development
Main analysis:
- Cognitive development assessed at 2½ years using the cognitive part of Bayley Scales of Infant and Toddler Development, third edition
Secondary analyses:
- Milestone development monitored prospectively by the parents using a registration form based on The Denver Development Index and WHO milestones registration (combined assessment by principal component analysis)
- Language development assessed at 1 and 2 years of age with the Danish version of The MacArthur Bates Communicative Developmental Inventory (CDI)
- The child´s general development (language, fine and gross motor, social and problem solving) at 3 years of age assessed with Ages and stages Questioner, third edition (ASQ-3)
Measured: 0-3 years
Growth
Main analysis:
- Body composition (fat mass and bone mineral density) assessed by DEXA scan at 3 years of age
Secondary analysis
- Development of BMI from birth to 3 years assesses longitudinally in the research clinic
Measured: 0-3 years
Systemic immune status
Main analysis Immune status at 18 months measured in stimulated whole blood as cytokine release (combined assessments by prinicipal component analyses)
Secondary analyses Composition of immune cell subsets in whole blood at birth and at 18 months of age
Measured: 18 months
Airway mucosal immune status
Immune status measured in airway mucosal lining fluid at 4 weeks and 2 years of age (combined assessments by prinicipal component analyses for each age point)
Measured: 4 weeks and 2 years
17q21 genotype and sphingolipid metabolites
In a secondary analyses, we will determine the effect of 17q21 genotype on the efficacy of vitamin D supplementation in the prevention of asthma/wheeze. We will compute hazard ratios for the reduction in asthma/wheeze risk associated with prenatal supplementation, stratified by rs12936231. rs12936231 is a functional SNP influencing expression of ORMDL3, and given the role of ORMDL3 as a key sphingolipid biosynthesis regulator, we will subsequently investigate the relative abundance of sphingolipids between those in the vitamin D Intervention arm and those in the placebo group, stratified by 17q21 genotype. Finally we will identify interactions between prenatal vitamin D supplementation, rs12936231 genotype and sphingolipid metabolism in the risk of asthma/wheeze by age three.
Measured: 6 months
Dental health
Caries and enamel defects (molar incisor hypomineralization, MIH) determined at a dental examination at age 6 years.
Measured: 6 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Mar 2009 (estimated)
- Study startMar 2009
- Primary completionJul 2027 (estimated)
- Study completionJul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (12)Papers the sponsor has linked to this study.
- Other trials for AsthmaStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 1
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 600 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Copenhagen Studies on Asthma in Childhood
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Klaus Bønnelykke, MD, PhD, Principal investigator, Copenhagen Studies on Asthma in Childhood
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT00856947
- Sponsor's protocol ID
- 2008-007871-26
- Other IDs
- 2008
- Acronym
- ABCvitaminD
- Status last verified
- Mar 2026
- First submitted
- 4 Mar 2009
- Last updated
- 19 Mar 2026
- Results posted
- No
- Data monitoring committee
- Yes
Publications
Frederiksen OF, Jepsen JRM, Brustad N, Vinding R, Rosenberg JB, Mohammadzadeh P, Hernandez-Lorca M, Schoos AM, Vahman N, Glenthoj BY, Fagerlund B, Bilenberg N, Bonnelykke K, Ebdrup BH, Aagaard K, Chawes B. High-Dose Vitamin D3 Supplementation During Pregnancy and Test-Based Cognitive Performance at Age 10 Years: A Post Hoc Secondary Analysis of a Randomized Clinical Trial. JAMA Netw Open. 2026 May 1;9(5):e2611464. doi: 10.1001/jamanetworkopen.2026.11464.
PubMed 42149595Brustad N, Wang T, Chen L, Kaiser H, Gomes B, Klein A, Vahman N, Skov L, Stokholm J, Schoos AM, Bonnelykke K, Chawes B. Effect of prenatal high-dose vitamin D on childhood atopic dermatitis is modified by maternal cotinine metabolome: A secondary analysis of a randomized clinical trial. J Am Acad Dermatol. 2026 Jan;94(1):88-95. doi: 10.1016/j.jaad.2025.08.044. Epub 2025 Aug 25.
PubMed 40865727Palacios C, Kostiuk LL, Cuthbert A, Weeks J. Vitamin D supplementation for women during pregnancy. Cochrane Database Syst Rev. 2024 Jul 30;7(7):CD008873. doi: 10.1002/14651858.CD008873.pub5.
PubMed 39077939Aagaard K, Mollegaard Jepsen JR, Sevelsted A, Horner D, Vinding R, Rosenberg JB, Brustad N, Eliasen A, Mohammadzadeh P, Folsgaard N, Hernandez-Lorca M, Fagerlund B, Glenthoj BY, Rasmussen MA, Bilenberg N, Stokholm J, Bonnelykke K, Ebdrup BH, Chawes B. High-dose vitamin D3 supplementation in pregnancy and risk of neurodevelopmental disorders in the children at age 10: A randomized clinical trial. Am J Clin Nutr. 2024 Feb;119(2):362-370. doi: 10.1016/j.ajcnut.2023.12.002. Epub 2023 Dec 9.
PubMed 38072183Brustad N, Yang L, Chawes BL, Stokholm J, Gurdeniz G, Bonnelykke K, Bisgaard H. Fish Oil and Vitamin D Supplementations in Pregnancy Protect Against Childhood Croup. J Allergy Clin Immunol Pract. 2023 Jan;11(1):315-321. doi: 10.1016/j.jaip.2022.09.027. Epub 2022 Sep 30.
PubMed 36184023Mohammadzadeh P, Rosenberg JB, Vinding R, Mollegaard Jepsen JR, Lindberg U, Folsgaard N, Erlang Sorensen M, Sulaiman D, Bilenberg N, Mitta Raghava J, Fagerlund B, Vestergaard M, Pantelis C, Stokholm J, Chawes B, Larsson H, Glenthoj BY, Bonnelykke K, Ebdrup BH, Bisgaard H. Effects of prenatal nutrient supplementation and early life exposures on neurodevelopment at age 10: a randomised controlled trial - the COPSYCH study protocol. BMJ Open. 2022 Feb 1;12(2):e047706. doi: 10.1136/bmjopen-2020-047706.
PubMed 35105560Knihtila HM, Kelly RS, Brustad N, Huang M, Kachroo P, Chawes BL, Stokholm J, Bonnelykke K, Pedersen CT, Bisgaard H, Litonjua AA, Lasky-Su JA, Weiss ST. Maternal 17q21 genotype influences prenatal vitamin D effects on offspring asthma/recurrent wheeze. Eur Respir J. 2021 Sep 23;58(3):2002012. doi: 10.1183/13993003.02012-2020. Print 2021 Sep.
PubMed 33653805Sass L, Vinding RK, Stokholm J, Bjarnadottir E, Noergaard S, Thorsen J, Sunde RB, McGrath J, Bonnelykke K, Chawes B, Bisgaard H. High-Dose Vitamin D Supplementation in Pregnancy and Neurodevelopment in Childhood: A Prespecified Secondary Analysis of a Randomized Clinical Trial. JAMA Netw Open. 2020 Dec 1;3(12):e2026018. doi: 10.1001/jamanetworkopen.2020.26018.
PubMed 33289844Brustad N, Garland J, Thorsen J, Sevelsted A, Krakauer M, Vinding RK, Stokholm J, Bonnelykke K, Bisgaard H, Chawes BL. Effect of High-Dose vs Standard-Dose Vitamin D Supplementation in Pregnancy on Bone Mineralization in Offspring Until Age 6 Years: A Prespecified Secondary Analysis of a Double-Blinded, Randomized Clinical Trial. JAMA Pediatr. 2020 May 1;174(5):419-427. doi: 10.1001/jamapediatrics.2019.6083.
PubMed 32091548Norrisgaard PE, Haubek D, Kuhnisch J, Chawes BL, Stokholm J, Bonnelykke K, Bisgaard H. Association of High-Dose Vitamin D Supplementation During Pregnancy With the Risk of Enamel Defects in Offspring: A 6-Year Follow-up of a Randomized Clinical Trial. JAMA Pediatr. 2019 Oct 1;173(10):924-930. doi: 10.1001/jamapediatrics.2019.2545.
PubMed 31381020Wolsk HM, Chawes BL, Litonjua AA, Hollis BW, Waage J, Stokholm J, Bonnelykke K, Bisgaard H, Weiss ST. Prenatal vitamin D supplementation reduces risk of asthma/recurrent wheeze in early childhood: A combined analysis of two randomized controlled trials. PLoS One. 2017 Oct 27;12(10):e0186657. doi: 10.1371/journal.pone.0186657. eCollection 2017.
PubMed 29077711Chawes BL, Bonnelykke K, Stokholm J, Vissing NH, Bjarnadottir E, Schoos AM, Wolsk HM, Pedersen TM, Vinding RK, Thorsteinsdottir S, Arianto L, Hallas HW, Heickendorff L, Brix S, Rasmussen MA, Bisgaard H. Effect of Vitamin D3 Supplementation During Pregnancy on Risk of Persistent Wheeze in the Offspring: A Randomized Clinical Trial. JAMA. 2016 Jan 26;315(4):353-61. doi: 10.1001/jama.2015.18318.
PubMed 26813208
Study at a glance
From the registry record, last updated by the sponsor on 19 Mar 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Vitamin D Supplementation During Pregnancy for Prevention of Asthma in Childhood: An Interventional Trial in the ABC (Asthma Begins in Childhood) Cohort
- ClinicalTrials.gov ID
- NCT00856947
- Acronym / sponsor ID
- ABCvitaminD / 2008-007871-26
- Conditions
- Asthma
- Keywords
- wheeze, infections, allergy, eczema, vitamin D
- Phase
- Phase 1
- Study type
- Interventional
- Recruitment status
- Active, not recruiting
- Enrolment
- 600 participants (estimated)
- Lead sponsor
- Copenhagen Studies on Asthma in ChildhoodUniversity, hospital or other
- Study start
- Mar 2009
- Primary completion
- Jul 2027 (estimated)
- Study completion
- Jul 2027 (estimated)
- First posted
- 6 Mar 2009 (estimated)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The aim of this study is to prevent asthma symptoms (recurrent wheeze) in childhood by supplementation with high dose vitamin D to the mother during pregnancy. Participants are mothers and children of the ABC (Asthma Begins in Childhood) cohort. Mothers are recruited during pregnancy and receive daily supplement with 2400 IU of Vitamin D3 or placebo from week 24 og gestation to 1 week after delivery. In addition all mothers are advised to take the recommended dose of 400 IU vitamin D daily. The mothers in ABC also participate in an interventional trial with fish oil supplementation, and the vitamin D randomization is stratified by fish oil treatment group. The child is followed with acute and planned vits at the research unit, and wheeze is diagnosed according to predefined algorithms.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Vitamin D | Active comparator | Dietary Supplement: Cholecalciferol D3Dietary supplement: 2400 IU Vitamin D3 (2 tablets of 1200 IU) from week 24 of gestation to 1 week after delivery |
| Placebo | Placebo comparator | Other: Placebo tabletPlacebo: 2 placebo tablets with no active substance, identical to the active tablets, from week 24 of gestation to 1 week after delivery |
Who may qualify
- Ages
- 18 years and older
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (6 listed)
- Pregnant in week 22-26 of gestation
- Participating in the ABC-cohort
- Living in Sealand, Denmark
- Fluent in Danish
- Willing to let the child participate in the study
Key exclusion criteria (6 listed)
- Intake of more than 400 IU of vitamin D during the last 6 months
- Endocrinological disease such as calcium metabolic disorder, parathyroid disorder, thyroid disorder or Diabetes type 1
- Tuberculosis
- Sarcoidosis
- In need of diuretics or heart medication including calcium channel blockers
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Cholecalciferol D3Also: Vitamin D from Camette, Denmark2 tablets of 1200 IU daily from week 24 of gestation to 1 week after delivery | Dietary supplement | Vitamin D |
| Placebo tabletAlso: Placebo tablets from Camette, Denmark2 tablets containing no active substance | Other | Placebo |
Primary outcome
Persistent wheeze
Time frame: 0 to 3 years of age
Age at onset of persistent wheeze diagnosed according to predefined algorithm of recurrent troublesome lung symptoms, response to treatment and relapse after withdrawal of treatment
12 secondary outcomes
Infections
Time frame: 0 to 3 years of age
Allergic sensitization
Time frame: 6 and 18 months of age
Eczema
Time frame: 0 to 3 years of age
Mothers levels of 25-OH-Vitamin D, PTH, Calcium, alkaline phosphatase
Time frame: 1 week after delivery
Growth
Time frame: 0 to 3 years of age
Asthma exacerbations
Time frame: 0 to 3 years of age
Neurological development
Time frame: 0-3 years
Growth
Time frame: 0-3 years
Systemic immune status
Time frame: 18 months
Airway mucosal immune status
Time frame: 4 weeks and 2 years
17q21 genotype and sphingolipid metabolites
Time frame: 6 months
Dental health
Time frame: 6 year
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 19 Mar 2026.
- Derived from this study: PubMed 42149595Frederiksen OF, Jepsen JRM, Brustad N, Vinding R, Rosenberg JB, Mohammadzadeh P, Hernandez-Lorca M, Schoos AM, Vahman N, Glenthoj BY, Fagerlund B, Bilenberg N, Bonnelykke K, Ebdrup BH, Aagaard K, Chawes B. High-Dose Vitamin D3 Supplementation During Pregnancy and Test-Based Cognitive Performance at Age 10 Years: A Post Hoc Secondary Analysis of a Randomized Clinical Trial. JAMA Netw Open. 2026 May 1;9(5):e2611464. doi: 10.1001/jamanetworkopen.2026.11464.
- Derived from this study: PubMed 40865727Brustad N, Wang T, Chen L, Kaiser H, Gomes B, Klein A, Vahman N, Skov L, Stokholm J, Schoos AM, Bonnelykke K, Chawes B. Effect of prenatal high-dose vitamin D on childhood atopic dermatitis is modified by maternal cotinine metabolome: A secondary analysis of a randomized clinical trial. J Am Acad Dermatol. 2026 Jan;94(1):88-95. doi: 10.1016/j.jaad.2025.08.044. Epub 2025 Aug 25.
- Derived from this study: PubMed 39077939Palacios C, Kostiuk LL, Cuthbert A, Weeks J. Vitamin D supplementation for women during pregnancy. Cochrane Database Syst Rev. 2024 Jul 30;7(7):CD008873. doi: 10.1002/14651858.CD008873.pub5.
- Derived from this study: PubMed 38072183Aagaard K, Mollegaard Jepsen JR, Sevelsted A, Horner D, Vinding R, Rosenberg JB, Brustad N, Eliasen A, Mohammadzadeh P, Folsgaard N, Hernandez-Lorca M, Fagerlund B, Glenthoj BY, Rasmussen MA, Bilenberg N, Stokholm J, Bonnelykke K, Ebdrup BH, Chawes B. High-dose vitamin D3 supplementation in pregnancy and risk of neurodevelopmental disorders in the children at age 10: A randomized clinical trial. Am J Clin Nutr. 2024 Feb;119(2):362-370. doi: 10.1016/j.ajcnut.2023.12.002. Epub 2023 Dec 9.
- Derived from this study: PubMed 36184023Brustad N, Yang L, Chawes BL, Stokholm J, Gurdeniz G, Bonnelykke K, Bisgaard H. Fish Oil and Vitamin D Supplementations in Pregnancy Protect Against Childhood Croup. J Allergy Clin Immunol Pract. 2023 Jan;11(1):315-321. doi: 10.1016/j.jaip.2022.09.027. Epub 2022 Sep 30.
- Derived from this study: PubMed 35105560Mohammadzadeh P, Rosenberg JB, Vinding R, Mollegaard Jepsen JR, Lindberg U, Folsgaard N, Erlang Sorensen M, Sulaiman D, Bilenberg N, Mitta Raghava J, Fagerlund B, Vestergaard M, Pantelis C, Stokholm J, Chawes B, Larsson H, Glenthoj BY, Bonnelykke K, Ebdrup BH, Bisgaard H. Effects of prenatal nutrient supplementation and early life exposures on neurodevelopment at age 10: a randomised controlled trial - the COPSYCH study protocol. BMJ Open. 2022 Feb 1;12(2):e047706. doi: 10.1136/bmjopen-2020-047706.
- Derived from this study: PubMed 33653805Knihtila HM, Kelly RS, Brustad N, Huang M, Kachroo P, Chawes BL, Stokholm J, Bonnelykke K, Pedersen CT, Bisgaard H, Litonjua AA, Lasky-Su JA, Weiss ST. Maternal 17q21 genotype influences prenatal vitamin D effects on offspring asthma/recurrent wheeze. Eur Respir J. 2021 Sep 23;58(3):2002012. doi: 10.1183/13993003.02012-2020. Print 2021 Sep.
- Derived from this study: PubMed 33289844Sass L, Vinding RK, Stokholm J, Bjarnadottir E, Noergaard S, Thorsen J, Sunde RB, McGrath J, Bonnelykke K, Chawes B, Bisgaard H. High-Dose Vitamin D Supplementation in Pregnancy and Neurodevelopment in Childhood: A Prespecified Secondary Analysis of a Randomized Clinical Trial. JAMA Netw Open. 2020 Dec 1;3(12):e2026018. doi: 10.1001/jamanetworkopen.2020.26018.
- Derived from this study: PubMed 32091548Brustad N, Garland J, Thorsen J, Sevelsted A, Krakauer M, Vinding RK, Stokholm J, Bonnelykke K, Bisgaard H, Chawes BL. Effect of High-Dose vs Standard-Dose Vitamin D Supplementation in Pregnancy on Bone Mineralization in Offspring Until Age 6 Years: A Prespecified Secondary Analysis of a Double-Blinded, Randomized Clinical Trial. JAMA Pediatr. 2020 May 1;174(5):419-427. doi: 10.1001/jamapediatrics.2019.6083.
- Derived from this study: PubMed 31381020Norrisgaard PE, Haubek D, Kuhnisch J, Chawes BL, Stokholm J, Bonnelykke K, Bisgaard H. Association of High-Dose Vitamin D Supplementation During Pregnancy With the Risk of Enamel Defects in Offspring: A 6-Year Follow-up of a Randomized Clinical Trial. JAMA Pediatr. 2019 Oct 1;173(10):924-930. doi: 10.1001/jamapediatrics.2019.2545.
- Derived from this study: PubMed 29077711Wolsk HM, Chawes BL, Litonjua AA, Hollis BW, Waage J, Stokholm J, Bonnelykke K, Bisgaard H, Weiss ST. Prenatal vitamin D supplementation reduces risk of asthma/recurrent wheeze in early childhood: A combined analysis of two randomized controlled trials. PLoS One. 2017 Oct 27;12(10):e0186657. doi: 10.1371/journal.pone.0186657. eCollection 2017.
- Derived from this study: PubMed 26813208Chawes BL, Bonnelykke K, Stokholm J, Vissing NH, Bjarnadottir E, Schoos AM, Wolsk HM, Pedersen TM, Vinding RK, Thorsteinsdottir S, Arianto L, Hallas HW, Heickendorff L, Brix S, Rasmussen MA, Bisgaard H. Effect of Vitamin D3 Supplementation During Pregnancy on Risk of Persistent Wheeze in the Offspring: A Randomized Clinical Trial. JAMA. 2016 Jan 26;315(4):353-61. doi: 10.1001/jama.2015.18318.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Klaus Bønnelykke, MD, PhD principal investigator
Copenhagen Studies on Asthma in Childhood
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 1 study testing Cholecalciferol D3 in people with Asthma, run by Copenhagen Studies on Asthma in Childhood at 2 sites in Denmark.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 6 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 19 Mar 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Denmark. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 1 studies test a treatment in a small group of people for the first time or in a new way, mainly to check safety and find the right dose.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Persistent wheeze (time frame: 0 to 3 years of age). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT00856947, which also lists 12 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 19 Mar 2026.