BCMO1 rs6564851: Understanding Beta-Carotene Conversion
The rs6564851 variant is a genetic polymorphism located near the BCMO1 gene, which plays a critical role in how your body processes dietary carotenoids. Research suggests this variant is associated with differences in the efficiency of converting beta-carotene into active vitamin A.
What each genotype means
Reduced beta-carotene conversion
This genotype is associated with lower enzymatic activity of the BCMO1 protein, which may result in less efficient conversion of dietary beta-carotene into vitamin A. Research suggests individuals with this profile may exhibit higher circulating levels of beta-carotene in the blood because it is not being converted as readily. This is a common genetic variation, and you should discuss your nutritional status and vitamin A intake with a healthcare professional.
This genotype is common, with the G allele appearing at a frequency of approximately 0.40–0.50 in European populations and roughly 0.25 in East Asian populations.
Intermediate beta-carotene conversion
This heterozygous genotype represents an intermediate state for BCMO1 enzyme activity compared to the homozygous variants. You may experience moderate efficiency in converting dietary beta-carotene into vitamin A. Because individual responses to dietary carotenoids vary significantly, consider consulting a nutritionist or clinician to evaluate your specific vitamin A and carotenoid levels.
This genotype is frequently observed in the general population, reflecting the high prevalence of both the G and T alleles across various ancestries.
Increased beta-carotene conversion
This genotype is associated with higher BCMO1 enzyme activity, which may facilitate more efficient conversion of dietary beta-carotene into vitamin A. Studies have linked this variant to lower circulating levels of beta-carotene in the blood, likely due to more rapid conversion. As this is a complex metabolic trait, please discuss your dietary needs and vitamin A status with a qualified healthcare provider.
This genotype is common, occurring in a significant portion of the population depending on the specific ancestral background.
What is rs6564851?
The rs6564851 variant is a single nucleotide polymorphism (SNP) located approximately 8,000 base pairs upstream of the BCMO1 gene on chromosome 16. In genetics, a SNP represents a variation at a single position in the DNA sequence. This specific variant is situated in a regulatory region that influences the expression of the BCMO1 gene. Because it sits in a promoter region, it is thought to affect how much of the BCMO1 enzyme is produced or how effectively it functions. Scientists study this location because it is part of a larger haplotype—a group of genetic markers inherited together—that has been consistently linked to circulating levels of carotenoids in the blood. By analyzing this specific site, researchers aim to understand why individuals may have different plasma concentrations of beta-carotene even when consuming similar amounts of plant-based foods.
The Role of the BCMO1 Gene
The BCMO1 gene, which stands for beta-carotene monooxygenase 1, provides instructions for creating an enzyme essential for vitamin A metabolism. This enzyme is primarily active in the small intestine, where it performs the oxidative cleavage of provitamin A carotenoids, such as beta-carotene, alpha-carotene, and beta-cryptoxanthin. By splitting these molecules, the enzyme converts them into retinaldehyde, which is subsequently reduced to retinol, the active form of vitamin A. Vitamin A is vital for numerous physiological processes, including vision, immune function, skin health, and embryonic development. When the BCMO1 enzyme functions at high efficiency, the body can effectively utilize plant-derived carotenoids to meet its vitamin A requirements. Conversely, variations that reduce the catalytic activity of this enzyme may lead to lower conversion rates, potentially impacting how an individual relies on dietary sources of vitamin A.
Research and Evidence Strength
The evidence linking rs6564851 to beta-carotene conversion is considered limited but scientifically significant. Several studies have observed that the T allele of this SNP is associated with altered enzymatic activity. Specifically, research has indicated that certain genotypes at this locus correlate with a reduced ability to convert beta-carotene into vitamin A, sometimes by as much as 50%. This reduction can lead to higher fasting blood concentrations of beta-carotene, as the body is less efficient at processing it. While these associations have been replicated in various cohorts, the clinical impact remains a subject of ongoing investigation. It is important to note that these findings are based on statistical associations in population studies and do not account for all factors influencing vitamin A status, such as overall diet, gut health, and other genetic modifiers. Therefore, this information should be viewed as a piece of a larger nutritional puzzle rather than a definitive health indicator.
Population Frequency
The frequency of the rs6564851 variant varies significantly across different ancestral populations. In European populations, the minor allele frequency is typically observed between 0.40 and 0.50. In contrast, other populations show different distributions; for example, some studies have noted that the minor allele is highly prevalent in Latin American populations, reaching frequencies around 0.70. These inter-ethnic variations highlight the importance of considering ancestry when interpreting genetic data. Because the variant is common in many groups, it is considered a standard polymorphism rather than a rare mutation. Understanding these frequency differences helps researchers contextualize why certain populations might show different average responses to dietary carotenoid intake in clinical studies.
Practical Considerations
Knowing your genotype for rs6564851 provides insight into your potential biological efficiency in converting plant-based carotenoids into vitamin A. However, this information cannot be used to diagnose a vitamin A deficiency or to prescribe specific dietary changes. If you are concerned about your vitamin A levels or nutritional status, it is essential to consult with a healthcare professional or a registered dietitian. They can evaluate your overall diet, blood markers, and health history to provide personalized guidance. Do not use genetic information to self-diagnose or alter your intake of supplements without professional oversight. Genetic testing for this variant is a tool for educational purposes, helping you understand your body's unique metabolic tendencies, but it should always be integrated into a comprehensive health plan managed by qualified medical experts.
How common is this variant?
The rs6564851 variant is common, with a minor allele frequency of approximately 0.40–0.50 in Europeans and around 0.25 in East Asian populations.
Frequently asked questions
Does rs6564851 mean I have a vitamin A deficiency?
No, this variant does not diagnose a deficiency. It only suggests a potential difference in how efficiently your body converts plant-based beta-carotene into active vitamin A.
Should I take vitamin A supplements if I have this variant?
You should not start or change any supplementation based on genetic results alone. Please discuss your nutritional needs and blood test results with a healthcare provider.
Can I change my BCMO1 gene expression?
You cannot change your DNA sequence. However, your overall vitamin A status is influenced by many factors, including your total dietary intake of both plant and animal-based vitamin A sources.
Is this variant the only thing that affects vitamin A levels?
No, vitamin A levels are influenced by a complex interplay of genetics, diet, gut health, and other metabolic factors. This SNP is only one small part of that process.
Sources & further reading
Educational information only, last refreshed 10/15/2026. Not medical advice — these associations describe population statistics, not individual predictions.
Curious what your genotype is for rs6564851?
Upload a raw DNA file from 23andMe, AncestryDNA, MyHeritage, or FamilyTreeDNA and see this variant — plus thousands more — interpreted in your full report.
Get my report — $29Related variants in BCMO1
Coding variant that exhibits an additive effect with rs12934922 in reducing enzymatic cleavage of dietary provitamin A carotenoids.
Missense variant in beta-carotene oxygenase 1 that significantly reduces catalytic efficiency of dietary beta-carotene conversion into active retinol.
This coding variant reduces beta-carotene 15,15'-monooxygenase activity, impairing the enzymatic conversion of provitamin A carotenoids into active retinal.