A Phase 3 interventional study of Cholecalciferol D3 and Olive oil in Asthma, Respiratory Tract Infections and Gastrointestinal Infection, sponsored by Professor Klaus Bønnelykke. Recruiting at 1 site in Denmark. Open to female participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-09-30.
Sponsored by Professor Klaus Bønnelykke · Phase 3, Interventional, and Prevention
The overall aim of the study is to develop a nutritional preventive vitamin D supplementation strategy in pregnancy for early childhood asthma/persistent wheeze during the first three years of life as we hypothesize that supplementation in higher doses than recommended could reduce the risk of disease development.
Randomization of 2000 pregnant women to vitamin D of high-dose (3200 IU/day) vitamin D vs placebo on top of the recommended 400 IU/day. Supplementation begins in gestational week 24 (22-26) until 1 week after delivery. Allocation to the trial will be determined based on the pre-interventional maternal blood levels of EPA+DHA with a dried blood screening test. Women with high levels (above 4.7% of total fatty acids) will be assigned to the vitamin D RCT. Maternal blood will be used for genetic, metabolomic and proteomic profiling. A 3-year follow-up of the children with longitudinal registration of parent reported symptoms, diagnoses, medication use, and hospitalizations will be performed. The primary outcome is persistent wheeze or asthma until age 3 years, with predefined analyses of effect modification by maternal genotypes. Secondary outcomes are lower respiratory tract infections, gastrointestinal infections, croup, troublesome lung symptoms, eczema, allergy, bone fractures, developmental milestones, mental health, cognition, and growth until age 3 years. A follow-up on both primary and secondary outcomes is planned after unblinding, from age 3 to 6 years.
4,841 studies on the registry are indexed under Asthma; 600 are open to participants now.
This study's planned enrollment of 2,000 is above the median of 78 across 3,341 interventional studies indexed under Asthma.
Browse Asthma studies →Professor Klaus Bønnelykke is the lead sponsor of 2 studies on the registry; 2 are open to participants now.
Counted across the registry records on this site, refreshed daily.
Oral intake of 1 capsule daily from week 22-26 of gestation until 1 week after delivery
Dietary Supplement: Cholecalciferol D3
Oral intake of 1 capsule daily from week 22-26 of gestation until 1 week after delivery
Other: Olive oil
Oral intake of 1 capsule per day from week 22-26 in pregnancy to 1 week after delivery
Also known as: D-Pearls, PharmaNord, DK
Oral intake of 1 capsule per day from week 22-26 in pregnancy to 1 week after delivery
Also known as: Placebo Pearls, PharmaNord, DK
Early childhood asthma/persistent wheeze age 0-3 years
Defined as either a) parental report of a minimum of 2 wheeze episodes with at least 1 after the child's second birthday and redemption of at least 2 prescriptions of asthma controller medication with at least 1 being after the child's second birthday or b) a minimum of 2 ED visits or hospitalizations due to asthmatic symptoms, and at least 1 of these being after the child's second birthday or c) parental report of physician-diagnosed asthma age 0-3 years Outcome analysis: risk (survival analysis) of persistent wheeze or asthma at age 0-3 years.
Time frame: 3 years
Atopic/non-atopic wheeze or asthma age 0-3 years
Parental reports of physician diagnosed asthma in combination with eczema and/or allergic rhinitis. Outcome analyses: asthma/persistent wheeze with/without eczema and/or allergic rhinitis (yes/no) by age 3 years. Each subtype is compared with children without asthma.
Time frame: 3 years
Troublesome lung symptoms age 0-3 years
Defined as cough, wheeze or dyspnea severely affecting the well-being of the child for at least 3 consecutive days based on parental reports. Outcome analyses: total no. of episodes with symptoms age 0-3 years.
Time frame: 3 years
Wheeze episodes age 0-3 years
Parental reports of wheezing. Outcome analyses: total no. of episodes with wheeze age 0-3 years.
Time frame: 3 years
Inhaled bronchodilator use from parental reports age 0-3 years
Outcome analyses: total no. of days with bronchodilator use age 0-3.
Time frame: 3 years
Inhaled bronchodilator prescriptions from medical record checks age 0-3 years
Outcome analyses: total no. of prescriptions age 0-3.
Time frame: 3 years
Asthma controller medication use from parental reports age 0-3 years
Outcome analyses: total no. of days with use of asthma controller medication age 0-3.
Time frame: 3 years
Asthma controller medication prescriptions from medical record checks age 0-3 years
Outcome analyses: total no. of prescriptions age 0-3.
Time frame: 3 years
Asthma hospitalizations or emergency department visits age 0-3 years
Outcome analyses: total no. of episodes age 0-3 years.
Time frame: 3 years
Eczema age 0-3 years
Parental reports of physician-diagnosed eczema and prescribed topical antiinflammatory medication on medical record checks. Outcome analyses: risk (survival analysis) of any eczema age 0-3 years and current eczema (yes/no) by age 3 years.
Time frame: 3 years
Allergic rhinitis age 0-3 years
Based on parental reports of physician-diagnosed allergic rhinitis. Outcome analyses: allergic rhinitis (yes/no) by age 3 years.
Time frame: 3 years
Food allergy 0-3 years
Parental reports of physician-diagnosed food allergy. Outcome analyses: any food allergy (yes/no) by age 3 years.
Time frame: 3 years
Lower respiratory tract infections age 0-3 years
Parental reports of physician-diagnosed bronchiolitis or pneumonia. Outcome analysis: risk (survival analysis) of first lower respiratory tract infection and total no. of lower respiratory tract infections age 0-3 years.
Time frame: 3 years
Gastrointestinal infections age 0-3 years
Parental reports. Outcome analyses: risk (survival analysis) of any gastroenteritis episode and total no. of gastroenteritis episodes age 0-3 years.
Time frame: 3 years
Croup age 0-3 years
Parental reports of physician diagnosed croup. Outcome analysis: risk (survival analysis) of any croup episode and total no. of croup episodes age 0-3 years.
Time frame: 3 years
Fever episodes age 0-3 years
Based on parental reports. Outcome analyses: total no. of episodes with symptoms age 0-3 years.
Time frame: 3 years
Absences from daycare age 0-3 years
Due to illnesses based on parental reports. Outcome analyses: total no. of absence days age 0-3 years.
Time frame: 3 years
Bone fractures age 0-3 years
Assessed by medical record checks including all radiologically verified fractures of larger long bones (i.e. clavicle, radius, ulna, tibia, fibula, femur and humerus). Outcome analyses: total no. of fractures age 0-3 years.
Time frame: 3 years
Developmental milestones age 0-3 years
Monitored every 6 months until age 3 years by the parents using a registration form based on The Denver Development Index and WHO milestones registration. Outcome analyses: combined assessment of age at achievement across milestones by principal component analysis.
Time frame: 3 years
Strength and difficulties at age 3 years
From the Strengths and Difficulties Questionnaire (SDQ), which is a brief behavioral screening questionnaire. Emotional symptoms: range 0-10, a low score means better outcome. Behavioral symptoms: range 0-10, a low score means better outcome. Hyperactivity/attention difficulties:range 0-10, a low score means better outcome. Problems with children of the same age:range 0-10, a low score means better outcome. Social strengths:range 0-10, a high score means better outcome. Impact on well-being and functioning: range 0-10, a low score means better outcome. Outcome analyses: SDQ scores at age 3 years.
Time frame: 3 years
BMI age 0-3 years
From parental reports every 6 months. Outcome analyses: development of BMI age 0-3 years and current BMI at age 3.
Time frame: 3 years
Waist circumference age 0-3 years
From parental reports every 6 months. Outcome analyses: development of waist circumference age 0-3 years and current waist circumference at age 3.
Time frame: 3 years
Persistent wheeze or asthma age 0-6 years
Defined similarly to the primary outcome Outcome analysis: risk (survival analysis) of persistent wheeze or asthma at age 0-6 years
Time frame: 6 years
Current asthma at age 6 years
Defined similarly to the primary outcome and with symptoms and/or asthma medication use in the last 12 months at age 6. Outcome analyses: Current wheeze or asthma (yes/no) by age 6 years.
Time frame: 6 years
Asthma or wheeze yearly prevalence 0-6 years
Defined as in the primary outcome and current disease defined from parental reports of wheeze and/or asthma medication use. Outcome analyses: Yearly prevalence of wheeze or asthma medication use (yes/no) 0-6 years.
Time frame: 6 years
Atopic/non-atopic asthma at age 6 years
Parental reports of physician diagnosed asthma in combination with eczema and/or allergic rhinitis. Outcome analyses: Current asthma with/without eczema and/or allergic rhinitis (yes/no) by age 6 years. Each subtype is compared with children without asthma.
Time frame: 6 years
Asthma controller medication 0-6 years
From redeemed medication prescriptions (inhaled corticosteroids and leukotriene modifiers) based on medical record checks: Outcome analyses: total no. of prescriptions age 0-6 years.
Time frame: 6 years
Inhaled bronchodilators age 0-6 years
From redeemed inhaled bronchodilators based on medical record checks. Outcome analyses: total no. of prescriptions age 0-6 years.
Time frame: 6 years
Asthma hospitalizations or emergency department visits age 0-6 years
Based on medical record checks. Outcome analyses: total no. of episodes age 0-6 years.
Time frame: 6 years
Eczema age 0-6 years
Based on parental reports of physician diagnosed eczema. Outcome analyses: risk (survival analysis) of any eczema age 0-6 years and current eczema (yes/no) by age 6 years.
Time frame: 6 years
Allergic rhinitis age 0-6 years
Based on parental reports of physician-diagnosed allergic rhinitis and on medical record checks. Outcome analyses: allergic rhinitis (yes/no) by age 6 years.
Time frame: 6 years
Food allergy age 0-6 years
Based on parental reports of physician-diagnosed food allergy. Outcome analyses: any food allergy (yes/no) by age 6 years.
Time frame: 6 years
Lower respiratory tract infections age 0-6 years
Based on parental reports of physician-diagnosed bronchiolitis or pneumonia. Outcome analysis: risk (survival analysis) of first lower respiratory tract infection and total no. of lower respiratory tract infections age 0-6 years.
Time frame: 6 years
Gastrointestinal infections age 0-6 years
Based on parental reports. Outcome analyses: risk (survival analysis) of any gastroenteritis episode and total no. of gastroenteritis episodes age 0-6 years.
Time frame: 6 years
Croup age 0-6 years
Based on parental reports of physician diagnosed croup. Outcome analysis: risk (survival analysis) of any croup episode and total no. of croup episodes age 0-6 years.
Time frame: 6 years
Bone fractures age 0-6 years
Assessed by medical record checks including all radiologically verified fractures of larger long bones (i.e. clavicle, radius, ulna, tibia, fibula, femur and humerus). Outcome analyses: total no. of fractures age 0-6 years.
Time frame: 6 years
Strength and difficulties at age 6 years
From the Strengths and Difficulties Questionnaire (SDQ), which is a brief behavioral screening questionnaire. Emotional symptoms: range 0-10, a low score means better outcome. Behavioral symptoms: range 0-10, a low score means better outcome. Hyperactivity/attention difficulties:range 0-10, a low score means better outcome. Problems with children of the same age:range 0-10, a low score means better outcome. Social strengths:range 0-10, a high score means better outcome. Impact on well-being and functioning: range 0-10, a low score means better outcome. Outcome analyses: SDQ scores at age 6 years.
Time frame: 6 years
ADHD symptoms at age 6 years
From the ADHD rating scale-IV preschool, a dimensional questionnaire for ADHD symptoms in preschool children. For attention symptoms: range: 0-27, a low score means better outcome. For impulsivity-hyperactivity: range: 0-27, a low score means better outcome. For behavioral problems: range: 0-24, a low score means better outcome. Outcome analyses: ADHD symptom scores at age 6 years.
Time frame: 6 years
Psychopathology screening at age 6 years
From the Child Behavior Check List; a questionnaire for general screening of preschool psychopathology. Total problem score: range 0-236, a low score means better outcome Internalizing problems score: range 0-64, a low score means better outcome Externalizing problems score: range 0-70, a low score means better outcome Outcome analyses: Total syndrome scales at age 6 years.
Time frame: 6 years
BMI age 0-6 years
From parental reports every 6 months. Outcome analyses: development of BMI age 0-6 years and current BMI at age 6.
Time frame: 6 years
Waist circumference age 0-6 years
From parental reports every 6 months. Outcome analyses: development of waist circumference age 0-6 years and current waist circumference at age 6.
Time frame: 6 years
ADHD symptoms at age 3 years
From the ADHD rating scale-IV preschool, a dimensional questionnaire for ADHD symptoms in preschool children. For inattentive score: range: 0-27, a low score means better outcome. For impulsivity-hyperactivity: range: 0-27, a low score means better outcome. Outcome analyses: ADHD symptom scores at age 3 years.
Time frame: 3 years
Social behavior assessment at age 3 years
From the Social Responsiveness Scale, Second Edition; a questionnaire for screening for autistic traits: Total score range: 0-195, a low score indicates better outcome. Outcome analyses: Total problem scores at age 3 years.
Time frame: 3 years
Social behavior assessment at age 6 years
From the Social Responsiveness Scale, Second Edition; a questionnaire for screening for autistic traits. Total score range: 0-195, low score indicates a better outcome. Outcome analyses: Total problem scores at age 6 years.
Time frame: 6 years
Psychopathology screening at age 3 years
From the Child Behavior Check List 1,5-5 years; a questionnaire for general screening of preschool psychopathology. Total problem score: range 0-198, a low score means better outcome Outcome analyses: Total syndrome scales at age 3 years.
Time frame: 3 years
Adaptive behavior at 3 years
Adaptive Behavior Assessment System, Third Edition (ABAS-3)is used to assess everyday, adaptive functioning. Total score range: 0-645, a low score indicate poorer outcome.
Time frame: 3 years
Adaptive behavior at 6 years
Adaptive Behavior Assessment System, Third Edition (ABAS-3)is used to assess everyday, adaptive functioning. Total score range: 0-633, a low score indicate poorer outcome.
Time frame: 6 years
Cognitive assessment age 0-3 years
From Behavior Rating Inventory of Executive Function in preschool children; a measurement of executive functions. Total problem score: range 63-189, a low score means better outcome. Outcome analyses: Index values at age 3 years.
Time frame: 3 years
Cognitive assessment age 0-6 years
From Behavior Rating Inventory of Executive Function in preschool children; a measurement of executive functions. Total problem score: range 60-180, a low score means better outcome. Outcome analyses: Index values at age 6 years.
Time frame: 6 years
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Professor Klaus Bønnelykke