An interventional study of Beta-carotene in Beta-carotene Bioavailability and Vitamin A Deficiency, sponsored by Newcastle-upon-Tyne Hospitals NHS Trust. Completed at 1 site in United Kingdom. Open to female participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2015-10-06.
Sponsored by Newcastle-upon-Tyne Hospitals NHS Trust · Not applicable, Interventional, and Basic science
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Summary:
Chronic intake of foods low in vitamin A (retinol) and provitamin A forming an unbalanced diet with little variety is common in young individuals in the United Kingdom (UK) population and can lead to subclinical micronutrient deficiency. Provitamin A sources such as β-carotene are cleaved centrally by the β-carotene 15,15'-monooxygenase (BCMO1) into retinal, the precursor of retinol. However, the amount of β-carotene and retinol produced after ingestion of β-carotene is highly variable between healthy individuals, with approximately 40% of the subjects being classified as low responders. Several stable isotope studies have shown a large disparity between the most efficient converters and the most inefficient converters of β-carotene with variations of up to 8-fold. It is possible that differences in β-carotene response may be due to single nucleotide polymorphisms (SNPs) in genes involved in aspects of β-carotene conversion. Previous work has shown that carriers of both, the 379V and 267S+379V BCMO1 variant alleles had a reduced ability to convert β-carotene. More importantly, 44% of the western population have the 379V haplotype. A high percentage of the Western population may therefore not be able to achieve adequate vitamin A intake if dietary β-carotene is a major source of their vitamin A intake. This is of particular relevance to vegetarians, to young individuals aged 19-24 years who have lower intakes of preformed retinol than any other age group, and to pregnant women. The aim of this study is to establish whether the maximum recommended dose for β-carotene of 7mg/day by the British Expert Committee on Vitamins and Minerals (EVM) can overcome the SNP effect in the BCMO1 enzyme.
Hypothesis:
The investigators hypothesize that the current maximum recommended intake of 7 mg of β-carotene per day cannot overcome the low convertor phenotype in BCMO1 to fulfill vitamin A requirements in these people.
67 studies on the registry are indexed under Vitamin A Deficiency; 7 are open to participants now.
This study's enrollment of 85 is below the median of 200 across 49 interventional studies indexed under Vitamin A Deficiency.
Browse Vitamin A Deficiency studies →Newcastle-upon-Tyne Hospitals NHS Trust is the lead sponsor of 67 studies on the registry; 5 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
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BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Beta-carotene 7mg formulation A
Dietary Supplement: Beta-carotene
Beta-carotene 7mg formulation B
Dietary Supplement: Beta-carotene
Beta-carotene 7mg formulation C
Dietary Supplement: Beta-carotene
Area under the plasma concentration versus time curve (AUC) of beta-carotene
Time frame: Pharmacokinetic measures (0,1,4,36,46,57,60 days post-dose)
Area under the plasma concentration versus time curve (AUC) of [13C]retinol
Time frame: Pharmacokinetic measures (0,1,2,3,4,8,10,22,36,46,57,58,59,60,64,66,78,92,113 days post-dose)
The record gives a start of Apr 2012, a primary completion of Sep 2014 and a completion of Sep 2014. It does not say whether these dates are actual or estimated.
How these figures are worked out, and which studies are left out of them.
This study is completed, as verified in Oct 2015. You cannot join it, but the record below documents what was studied.
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Studies of the drug tested here: Beta Carotene
Newcastle-upon-Tyne Hospitals NHS Trust