A Household-Based Dietary Intervention Study of Vitamin D Fortified Bread in Irish Families (NCT07481240) | Clinical Trial Compass
CompletedNot Applicable
A Household-Based Dietary Intervention Study of Vitamin D Fortified Bread in Irish Families
Ireland128 participantsStarted 2025-11-17
Plain-language summary
Vitamin D deficiency is common. It is caused by limited sun availability together with a low supply of vitamin D in the food system. There is a high prevalence of low vitamin D status around the world. In Ireland, our relatively northern latitude and prevailing weather mean that UVB availability for skin synthesis of vitamin D is limited in this country and our population relies on the dietary supply of vitamin D to prevent deficiency. Thus, the endemic Irish problem of vitamin D malnutrition is due to the lack of vitamin D in our food system. Dietary guidelines cannot address this issue because foods naturally rich in vitamin D are very few and infrequently consumed.
The FamDBread study will test the hypothesis that a vitamin D-fortified bread as part of a healthy diet that includes vitamin D-fortified foods is effective in preventing low vitamin D status during winter, and safe for families to consume.
Who can participate
Age range
5 Years – 59 Years
Sex
ALL
See this in plain English?
AI-rewrites the medical criteria so a patient or caregiver can understand them. Always confirm with the trial site.
Inclusion criteria
. Provide written informed consent if over 16 years; informed parental consent for children under-16 years, plus age-appropriate assent for children under-16 years.
. Be a household with at least one adult ≥18 years, with at least one dependent aged 5 years or older.
. Willing to consume bread provided and have storage capacity for frozen bread.
. Be in good general health.
. Be willing to follow the assigned diet for 8 weeks and attend the required appointments.
Exclusion criteria
. Daily consumption of a vitamin D supplement with a dose exceeding \>10µg/d (400 IU) equivalent.
Questions worth asking your doctor
Bring these to your next appointment. They're a starting point for a shared conversation — not a sign you qualify or a recommendation to enrol.
1Based on my diagnosis and history, is this trial worth exploring for me — or is there a standard treatment we should try first?
2What does this trial's phase tell us about how much is already known about its safety and benefit?
3What would taking part actually involve for me — visits, tests, time, and travel?
4What are the known and possible risks or side effects I should weigh, and how would they be monitored?
5If this trial isn't the right fit, what other options or trials would you suggest I look into?
Generated to help you prepare — always confirm anything about your own eligibility and care with the study team and your doctor.
Questions for the trial coordinator
The trial coordinator is the person who runs the study day to day. These cover the practical side — logistics, costs, and what taking part would actually mean for your life. The study team confirms whether you meet the criteria; these are questions to ask, not a sign you qualify.
1What does taking part actually involve week to week — how many visits, where, and how long does each one take?
2What costs are covered by the study, and what might I have to pay for myself, including travel, parking, or time off work?
3What happens during screening, and what happens if the study team confirms I don't meet the criteria after those tests?
4Who pays for the scans, blood work, and other tests the trial requires — the study, my insurance, or me?
5How will being in the trial affect my regular care, and will my own doctor stay informed and involved?
6Can I leave the trial at any point if I change my mind, and what would happen to my care if I do?
A starting point for the conversation — always confirm anything about your own eligibility, costs, and care with the study team and your doctor.
What they're measuring
1
Serum concentrations of 25-hydroxyvitamin D (25(OH)D)
. Exposure to factors that may influence vitamin D status, such as winter sun holiday, ski holiday, tanning beds etc.
. Are following a medically prescribed diet.
. Have a diagnosis of a medical condition that may interfere with vitamin D absorption, such as Coeliac disease, Inflammatory Bowel Disease, cystic fibrosis, or metabolism, such as liver disease, renal disease.
. Have a history of active cancer or a diagnosis of cancer within the past 5 years.
. Have an allergy to the bread ingredients.
. Are participating in another research study with an intervention or other lifestyle programme that would interfere with the outcomes of the study.
. Are unable to read, write, or understand English.