CYP2R1 rs10741657: What Your Genotype Means for Vitamin D
The rs10741657 variant is a common genetic polymorphism located in the CYP2R1 gene. It is widely recognized in genomic research for its association with circulating levels of 25-hydroxyvitamin D, the primary form of vitamin D measured in the blood.
What each genotype means
Higher vitamin D potential
Research indicates that individuals with the AA genotype tend to have higher circulating levels of 25-hydroxyvitamin D compared to those with the G allele. This variant is located in the 5'-UTR region of the CYP2R1 gene, which may influence the expression of the enzyme responsible for activating vitamin D. Please discuss your vitamin D status and any supplementation needs with your healthcare provider.
This genotype is generally less common than the G-allele containing genotypes in many studied populations.
Intermediate vitamin D potential
Carriers of the AG genotype typically show intermediate levels of 25-hydroxyvitamin D compared to the AA and GG genotypes. This genetic variation in the CYP2R1 gene is associated with how your body processes vitamin D, though individual levels are also heavily influenced by diet, sun exposure, and lifestyle. You should consult with your clinician or pharmacist to determine if your vitamin D levels are optimal.
This is a common genotype observed across many diverse populations.
Lower vitamin D potential
The GG genotype is associated with a trend toward lower circulating 25-hydroxyvitamin D levels in various population studies. Because this variant may affect the efficiency of the CYP2R1 enzyme, you may have a different baseline requirement for maintaining adequate vitamin D levels. Please discuss your vitamin D status and potential supplementation with your healthcare provider.
This is a common genotype found frequently in many global populations.
Understanding the rs10741657 Variant
The rs10741657 variant is a single nucleotide polymorphism (SNP) situated on chromosome 11 within the CYP2R1 gene region. Specifically, this variant is often described as being located in the 5'-UTR, a non-coding regulatory region of the gene. Because it sits in a regulatory area, researchers hypothesize that it may influence how much of the CYP2R1 enzyme is produced or how efficiently it functions. In the context of human genetics, rs10741657 is one of the most frequently studied markers regarding vitamin D metabolism. It serves as a key example of how common genetic variation can contribute to the natural diversity in biochemical markers between individuals. While it is a single point of change in the DNA sequence, its consistent appearance in large-scale genome-wide association studies (GWAS) highlights its role as a significant genetic determinant of vitamin D status.
The Role of the CYP2R1 Gene
The CYP2R1 gene provides instructions for creating an enzyme known as vitamin D 25-hydroxylase. This enzyme is critical for the body's processing of vitamin D, whether that vitamin is obtained through dietary intake or synthesized in the skin via exposure to sunlight. Once vitamin D enters the bloodstream, it must undergo a two-step activation process to become biologically active. The first step, which occurs primarily in the liver, is the conversion of vitamin D into 25-hydroxyvitamin D by the 25-hydroxylase enzyme. This 25-hydroxyvitamin D is the major circulating form of the vitamin and is the standard marker used by clinicians to assess a person's vitamin D status. If the CYP2R1 enzyme is less efficient due to genetic variation or other factors, the conversion process may be altered, potentially impacting the total amount of 25-hydroxyvitamin D available in the body.
Research and Evidence Strength
The association between rs10741657 and vitamin D levels is supported by moderate to strong evidence from multiple large-scale genome-wide association studies. Researchers have consistently observed that the G allele is associated with lower circulating levels of 25-hydroxyvitamin D compared to the A allele. While these statistical associations are robust across many cohorts, it is important to note that vitamin D levels are also heavily influenced by environmental factors, such as sun exposure, diet, and supplementation. Therefore, while this variant is a significant genetic contributor, it is only one piece of a complex puzzle. Furthermore, while rare, pathogenic mutations in the CYP2R1 gene can lead to vitamin D-dependent rickets type 1B, a severe condition. It is crucial to distinguish these rare, high-impact mutations from the common rs10741657 variant, which is associated with normal physiological variation rather than disease.
Population Frequency and Interpretation
The rs10741657 variant is common across many global populations, meaning that both the A and G alleles are frequently found in the general public. Because it is a common variant, most people carry at least one copy of the G or A allele. When interpreting this information, it is essential to understand that having a specific genotype does not constitute a medical diagnosis. Genetic markers like rs10741657 provide insight into biological tendencies, not clinical outcomes. If you are concerned about your vitamin D levels, the most accurate approach is to consult with a healthcare provider who can order a blood test to measure your actual 25-hydroxyvitamin D levels. Never use genetic information to make decisions about supplementation or medication without professional guidance, as individual needs vary significantly based on health history and lifestyle.
How common is this variant?
The rs10741657 variant is common in many populations, with the minor allele frequency reported at approximately 0.33 in major databases.
Frequently asked questions
Does my rs10741657 genotype mean I have a vitamin D deficiency?
No, this variant is associated with natural variation in vitamin D levels, not a clinical diagnosis of deficiency. A blood test ordered by your doctor is the only way to determine your actual vitamin D status.
Should I take more vitamin D if I have the G/G genotype?
You should not change your supplement regimen based on genetic results alone. Please discuss your vitamin D levels and any potential supplementation needs with your healthcare provider or pharmacist.
Is rs10741657 the same as the mutations that cause rickets?
No, rs10741657 is a common variant associated with normal physiological differences. Pathogenic mutations that cause vitamin D-dependent rickets type 1B are rare and distinct from this common SNP.
How does the CYP2R1 gene affect my health?
The CYP2R1 gene produces an enzyme that helps your body activate vitamin D. Variations in this gene can influence how efficiently your body converts vitamin D into its circulating form.
Sources & further reading
Educational information only, last refreshed 9/23/2026. 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.
This variant in the CYP2R1 gene, which encodes a key vitamin D 25-hydroxylase, is associated with altered serum 25-hydroxyvitamin D concentrations.
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.
Affects the body's ability to convert sunlight into active Vitamin D.