CYP2R1 rs1074145: What Your Genotype Means
The rs1074145 variant is a common genetic change located within the CYP2R1 gene. Research suggests this variant is associated with variations in serum 25-hydroxyvitamin D concentrations, which are key markers of vitamin D status in the body.
What each genotype means
Typical 25-hydroxylase activity
You carry two copies of the G allele, which is the ancestral and major allele in most human populations. Research has associated this genotype with typical enzymatic conversion of vitamin D into 25-hydroxyvitamin D [25(OH)D]. However, individual circulating vitamin D levels depend heavily on sun exposure, dietary intake, and overall health.
Carried by approximately 35% to 40% of people of European ancestry and over 70% of people of East Asian ancestry.
Slightly lower vitamin D conversion
You carry one copy of the A variant allele and one copy of the G allele. Genome-wide association studies have linked this genotype to modestly lower circulating 25-hydroxyvitamin D concentrations compared to the GG genotype. The clinical impact of this single variant is modest, and overall vitamin D status is influenced by lifestyle, geography, and dietary habits.
Carried by roughly 45% to 50% of people of European ancestry and about 25% of individuals of East Asian descent.
Reduced circulating vitamin D baseline
You carry two copies of the A variant allele. Observational and genome-wide association studies have consistently correlated this genotype with lower baseline serum 25-hydroxyvitamin D levels compared to AG or GG carriers. Evidence suggests this allele increased in frequency in higher-latitude populations, but maintaining healthy vitamin D levels through nutrition and sunlight remains readily achievable.
Found in roughly 15% to 18% of individuals of European ancestry, but in fewer than 3% of individuals of East Asian descent.
Understanding the rs1074145 Variant
The rs1074145 variant is a single nucleotide polymorphism (SNP) situated within the CYP2R1 gene on chromosome 11. In genetics, a SNP represents a variation at a single position in the DNA sequence among individuals. Because this variant is located in a region associated with the regulation of vitamin D metabolism, researchers have studied it extensively to understand how it might influence the body's ability to process vitamin D. It is important to note that while this SNP is frequently discussed in the context of vitamin D levels, it is just one of many genetic and environmental factors—such as diet, sun exposure, and overall health—that contribute to an individual's vitamin D status.
The Role of the CYP2R1 Gene
The CYP2R1 gene provides instructions for making an enzyme called vitamin D 25-hydroxylase. This enzyme plays a critical role in the body's vitamin D pathway by converting vitamin D into 25-hydroxyvitamin D, which is the primary circulating form of the vitamin in the blood. This conversion is a necessary step before the body can further activate vitamin D into its hormone-like form, which then binds to the vitamin D receptor to regulate various physiological processes. When the CYP2R1 gene functions optimally, it helps maintain stable levels of 25-hydroxyvitamin D. Research into this gene has been vital for understanding rare conditions like vitamin D hydroxylation-deficient rickets, as well as more common variations in how individuals maintain their vitamin D levels.
Research and Evidence Strength
Scientific evidence linking rs1074145 and other nearby CYP2R1 variants to serum 25-hydroxyvitamin D concentrations is supported by various genome-wide association studies (GWAS). These studies have consistently identified the CYP2R1 locus as a significant contributor to inter-individual differences in vitamin D levels. However, the evidence strength for this specific variant is often categorized as limited or moderate in terms of clinical utility, as the actual impact on an individual's health outcomes remains complex. While some studies suggest associations between CYP2R1 variants and other health markers, such as cardiovascular health, these findings are often specific to certain populations or require further validation. It is essential to view these statistical associations as indicators of biological trends rather than definitive predictors of personal health or disease risk.
Population Frequency
The rs1074145 variant is considered a common SNP, though its frequency varies significantly across different ancestral populations. Because allele frequencies are not uniform globally, the prevalence of specific genotypes will differ depending on an individual's genetic background. Researchers use these frequency differences to better understand the evolutionary history of the gene and to ensure that genetic studies are representative of diverse groups. If you are interested in how common this variant is in your specific ancestral group, databases like gnomAD provide detailed frequency data based on large-scale population sequencing efforts.
Interpreting Your Genetic Information
Understanding your genotype for rs1074145 can be an interesting way to learn about your genetic predispositions, but it should not be used to make medical decisions. Genetic variants are only one piece of a much larger puzzle that includes your lifestyle, environment, and overall medical history. If you are concerned about your vitamin D levels, the most reliable approach is to consult with a healthcare provider who can order a blood test to measure your actual serum 25-hydroxyvitamin D concentration. Never use genetic information to self-diagnose or to alter your intake of supplements or medications. Always discuss any questions regarding your health, nutrition, or potential supplementation with a qualified clinician or pharmacist who can provide personalized guidance based on your clinical needs.
How common is this variant?
This is a common variant, though allele frequencies vary significantly by ancestral population.
Frequently asked questions
Does this variant mean I have a vitamin D deficiency?
No, having a specific genotype for rs1074145 does not mean you have a vitamin D deficiency. Vitamin D levels are primarily determined by environmental factors like sun exposure and diet, and a blood test is the only way to accurately assess your current status.
Should I take more vitamin D if I have this variant?
You should not change your supplement regimen based on a genetic variant. Please consult with your doctor or pharmacist to determine if supplementation is appropriate for your specific health needs.
Is this variant linked to any diseases?
While some research has explored associations between CYP2R1 variants and various health conditions, the evidence is often limited or mixed. These associations are statistical in nature and do not imply a direct cause-and-effect relationship for individuals.
Where can I find more information about my specific genotype?
You can look up your rsID in public databases like the NCBI SNP database or the GWAS Catalog. These resources provide summaries of published research regarding the variant's associations.
Sources & further reading
Educational information only, last refreshed 10/15/2026. Not medical advice — these associations describe population statistics, not individual predictions.
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This variant is associated with variations in Vitamin D metabolism and circulating levels of 25(OH)D.
Associated with altered hepatic 25-hydroxylase enzyme levels and baseline circulating serum 25-hydroxyvitamin D concentrations.
Influences hepatic 25-hydroxylation efficiency and circulating 25-hydroxyvitamin D concentrations.
This variant in the CYP2R1 gene is associated with circulating 25-hydroxyvitamin D levels and, in rare cases, pathogenic variants in this gene can cause vitamin D-dependent rickets type 1B.
Affects the body's ability to convert sunlight into active Vitamin D.