What you carry at this position in your DNA and what research says about it.
Osteoporosis Risk: 5/10 evidence, 54 publications.
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Sample genotype (not yours): C/C
Lower Risk of Osteoporosis
You carry two copies of the protective allele, which is linked to stronger bone mineral density and a lower risk of bone disorders. You are also likely to respond exceptionally well to certain bone-strengthening medications.
What this genotype means: Lower risk of osteoporosis; Enhanced bone density response to alendronate; Typical risk of asthma.
Sample genotype (not yours): C/T
Typical Risk of Osteoporosis
You carry one protective allele and one risk allele, resulting in an intermediate or typical risk of low bone mineral density. Your body maintains a balanced baseline for bone health and vitamin D receptor function.
What this genotype means: Typical risk of osteoporosis; Average response to bone medications; Typical height and asthma risk.
Sample genotype (not yours): T/T
Higher Risk of Osteoporosis
You carry two copies of the risk allele, which is associated with lower bone mineral density and a higher susceptibility to osteoporosis. You may also have a slightly reduced response to standard bone-building therapies.
What this genotype means: Increased risk of osteoporosis; Reduced bone density improvement on alendronate; Slightly higher risk of asthma.
Gene function and biological role
Gene Function: The VDR gene encodes the vitamin D receptor, a nuclear hormone receptor that binds to the active form of vitamin D. This receptor plays a central role in calcium absorption, bone mineralization, and maintaining skeletal health. Beyond bone metabolism, the receptor is expressed in immune cells and tissues throughout the body, influencing inflammatory pathways and immune responses. Variations in this gene can alter receptor expression levels and stability, affecting how efficiently the body utilizes vitamin D. Consequently, VDR is widely studied for its impact on bone density, immune health, and drug metabolism.
Variant Impact: The rs1544410 variant, historically known as the BsmI polymorphism, is located in an intron near the end of the VDR gene. While it does not change the amino acid sequence of the receptor protein, it is in strong linkage disequilibrium with other functional variants that regulate VDR messenger RNA stability and overall receptor expression. This genetic change influences how the body processes calcium and maintains bone mineral density. It also affects the expression of metabolic enzymes in the gut, altering the processing of certain medications.
Key Insight: This variant acts as a genetic thermostat for vitamin D receptor expression, indirectly shaping bone strength and even influencing how quickly your body processes common sedatives.
Location: VDR. Chromosome 12 · 12q13.11 · 47.8 Mb
Estimated prevalence by population
Global 43.0%; European 35.7%; African 48.6%; East Asian 87.6%; South Asian 30.7%; Americas 48.1%; Ashkenazi 40.7%; Finnish 44.6%; Middle Eastern 40.6%; Amish 51.9%.
Estimated CC genotype frequency.
Global 44.3%; European 48.1%; African 42.2%; East Asian 12.0%; South Asian 49.4%; Americas 42.5%; Ashkenazi 46.2%; Finnish 44.4%; Middle Eastern 46.2%; Amish 40.3%.
Estimated CT genotype frequency.
Global 12.6%; European 16.2%; African 9.2%; East Asian 0.4%; South Asian 19.8%; Americas 9.4%; Ashkenazi 13.1%; Finnish 11.1%; Middle Eastern 13.2%; Amish 7.8%.
Estimated TT genotype frequency.
Showing effects for C/C genotype
Organ Systems
Bone, Joint & Connective Tissue Health
Osteoporosis. Evidence: 4/10. Source: PMID 30233789. Decreased Risk.
Alendronate Response. Evidence: 5/10. Source: PMID 12608943. Stronger Response.
Respiratory Health
Asthma. Evidence: 3/10. Source: PMID 31654764. Typical Risk.
Lifestyle, Fitness & Aging
Height & Body Size
Height. Evidence: 3/10. Source: PMID 28617856. Typical Height.
Pharmacogenomics
Anesthesia Response
Midazolam Metabolism. Evidence: 5/10. Source: PMID 22484315. Faster Metabolism.
Antimicrobial & Antiviral Response
Hepatitis C Therapy Anemia. Evidence: 5/10. Source: PMID 25713999. Typical Risk.
Showing effects for C/T genotype
Osteoporosis. Evidence: 4/10. Source: PMID 30233789. Intermediate Risk.
Alendronate Response. Evidence: 5/10. Source: PMID 12608943. Typical Response.
Showing effects for T/T genotype
Osteoporosis. Evidence: 4/10. Source: PMID 30233789. Increased Risk.
Alendronate Response. Evidence: 5/10. Source: PMID 12608943. Poorer Response.
Asthma. Evidence: 3/10. Source: PMID 31654764. Increased Risk.
Height. Evidence: 3/10. Source: PMID 28617856. Shorter Stature.
Midazolam Metabolism. Evidence: 5/10. Source: PMID 22484315. Slower Metabolism.
Hepatitis C Therapy Anemia. Evidence: 5/10. Source: PMID 25713999. Increased Risk.
What this genotype means for the people who carry it
Sample genotype: CC (Homozygous)
Having the C/C genotype is associated with a lower risk of developing low bone mineral density disorders and osteoporosis. Clinical studies indicate that individuals with this genotype experience better bone density preservation and a lower rate of bone loss over time. If treated with the osteoporosis medication alendronate, people with this genetic profile tend to show significantly greater improvements in bone mineral density compared to other genotypes. Additionally, this genotype is linked to a typical risk of asthma and typical height. In terms of drug processing, C/C carriers tend to metabolize the sedative midazolam more rapidly due to higher intestinal enzyme activity.
Lower risk of osteoporosis; Enhanced bone density response to alendronate; Typical risk of asthma.
Sample genotype: CT (Heterozygous)
Carrying the C/T genotype places you in the intermediate range for bone mineral density and osteoporosis risk. Studies suggest that your rate of bone loss and overall bone strength are close to the population average. Your response to bone-strengthening medications like alendronate is expected to be typical, without the heightened benefit seen in C/C carriers or the reduced response seen in T/T carriers. This genotype is also associated with a typical risk of asthma and a typical height profile. Furthermore, you are likely to metabolize certain medications, such as the sedative midazolam, at a typical to fast rate.
Typical risk of osteoporosis; Average response to bone medications; Typical height and asthma risk.
Sample genotype: TT (Homozygous)
Having the T/T genotype is linked to an increased risk of low bone mineral density and a higher susceptibility to osteoporosis. Research indicates that individuals with this genetic profile may experience faster bone loss, particularly later in life. When treated with the common osteoporosis medication alendronate, T/T carriers often show less improvement in bone density compared to those with other genotypes. This genetic variant is also associated with a slightly higher susceptibility to asthma and a tendency toward a shorter stature. Additionally, if undergoing specific antiviral treatments for Hepatitis C, this genotype is associated with an elevated risk of developing treatment-induced anemia.
Increased risk of osteoporosis; Reduced bone density improvement on alendronate; Slightly higher risk of asthma.
Variants with shared genetic architecture
rs739837 · VDR Gene · Chr 12 · Skin Cancer Risk
rs11568820 · VDR Gene · Chr 12 · Bone Health and Density
rs731236 · VDR Gene · Chr 12 · Breast Cancer Prognosis
Content updated August 2026.
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