Effect of SNPs in the BCMO1 Enzyme (BETASNP2)
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ClinicalTrials.gov Identifier: NCT02276014 |
Recruitment Status :
Completed
First Posted : October 27, 2014
Last Update Posted : October 6, 2015
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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.
Condition or disease | Intervention/treatment | Phase |
---|---|---|
Beta-carotene Bioavailability Vitamin A Deficiency | Dietary Supplement: Beta-carotene | Not Applicable |
Study Type : | Interventional (Clinical Trial) |
Actual Enrollment : | 85 participants |
Allocation: | Randomized |
Intervention Model: | Parallel Assignment |
Masking: | Single (Participant) |
Primary Purpose: | Basic Science |
Official Title: | Effect of SNPs in the Beta-carotene 15, 15'-Monooxygenase (BCMO1) Enzyme on Retinol Formation and Beta-carotene Plasma Responses |
Study Start Date : | April 2012 |
Actual Primary Completion Date : | September 2014 |
Actual Study Completion Date : | September 2014 |

Arm | Intervention/treatment |
---|---|
Supplement A
Beta-carotene 7mg formulation A
|
Dietary Supplement: Beta-carotene |
Supplement B
Beta-carotene 7mg formulation B
|
Dietary Supplement: Beta-carotene |
Supplement C
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) ]

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Ages Eligible for Study: | 18 Years to 45 Years (Adult) |
Sexes Eligible for Study: | Female |
Accepts Healthy Volunteers: | Yes |
Inclusion Criteria:
- Healthy individual.
- Female.
- Between 18 and 45 years of age.
- Caucasian.
- BMI between 18 and 30 kg/m2.
- Subject willing and able to give written informed consent.
Exclusion Criteria:
- Smoking.
- Diabetes.
- Gastrointestinal diseases.
- Renal and hepatic diseases.
- Hyperlipidaemia.
- Preformed dietary retinol intake above 60% of reference nutrient intake (RNI) values.
- Recreational drug use.
- Multi-vitamin consumption.
- Pregnancy.
- Menopause.
- Allergy or sensitivity to study products or ingredients.
- Blood donation 3 months prior to screening.
- Participation in other clinical study 4 weeks prior to study start.
- Suspected inability or unwillingness to comply with study procedures.

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02276014
United Kingdom | |
Newcastle NIHR Clinical Research Facility, Royal Victoria Infirmary | |
Newcastle upon Tyne, Tyne & Wear, United Kingdom, NE1 4LP |
Principal Investigator: | Georg Lietz, PhD | Newcastle University |
Responsible Party: | Newcastle-upon-Tyne Hospitals NHS Trust |
ClinicalTrials.gov Identifier: | NCT02276014 |
Other Study ID Numbers: |
2011-01-18-BETASNP2 REC 11/NE/0211 ( Other Identifier: National Research Ethics Service (NRES) ) |
First Posted: | October 27, 2014 Key Record Dates |
Last Update Posted: | October 6, 2015 |
Last Verified: | October 2015 |
Beta carotene Retinol |
Night Blindness Vitamin A Deficiency Avitaminosis Deficiency Diseases Malnutrition Nutrition Disorders Vision Disorders Eye Diseases Beta Carotene Carotenoids |
Antioxidants Molecular Mechanisms of Pharmacological Action Protective Agents Physiological Effects of Drugs Provitamins Vitamins Micronutrients Nutrients Growth Substances |