Vitamin D Receptor (VDR): An Introduction
The Vitamin D receptor (VDR) gene is associated with the synthesis of Vitamin D receptor, a cell membrane receptor that binds to vitamin D.
Specific alleles of this gene are known to either increase or decrease the sensitivity of the body to the effects of Vitamin D. This receptor is involved in the intestinal transport of calcium, iron and other minerals.
Variants of the gene are shown to be associated with changes in the levels of vitamin D levels and power.
Vitamin D plays an important role in stimulating calcium absorption and also in bone mineralization by promoting osteoblast differentiation.
Association with Vitamin D levels:
The taq1 polymorphism (rs731236) of the VDR gene is associated with Vitamin D levels among Indians. People with the T variant of the gene were associated with lower serum vitamin D levels.
Association with Power:
A study conducted on identifying handgrip strength, which is indicative of muscle strength, showed that there was a significant association between taq1 polymorphism and muscle strength.
People with the C variant of the gene are found to be better at power-based activities than endurance.
| Genotype rs731236 | Phenotype | Recommendations |
| CC | [Advantage] More likely to have higher Vitamin D levels [Advantage] Better muscle growth and bone density on strength training | Likely normal levels of vitamin D Include vitamin D rich food in the diet like fish and eggs Include strength and power training in the fitness regimen |
| CT | [Advantage] More likely to have higher Vitamin D levels [Advantage] Better muscle growth and bone density on strength training | Likely normal levels of vitamin D Include vitamin D rich food in the diet like fish and eggs Include strength and power training in the fitness regimen |
| TT | [Limitation] More likely to have lower Vitamin D levels [Limitation] Lower level of muscle growth and bone density on strength training | Likely lower vitamin D levels Spend time outdoors under the sun and include vitamin D rich foods in the diet |
What is vitamin D deficiency?
Vitamin D is responsible for bone strength in the human body.
It helps the body utilize the calcium absorbed from the diet effectively.
Some natural sources of vitamin D include sunlight and a variety of foods like fish, egg yolk, fortified dairy and grain products, etc.
Insufficient vitamin D supply causes a serious condition called vitamin D deficiency.
Approximately, 1 billion individuals worldwide, that is, nearly 15% of the world's population have this deficiency.
What are the signs of vitamin D deficiency?
Most people tend to oversee the signs and fail to realize that they have this deficiency. Here is what can be looked out for:
- Bone pain and bone loss
- Falling sick frequently
- Fatigue
- Slow healing of wounds
- Muscle pain
- Hair loss
- Depression
- Compromised immune system
What are the risk factors or causes of vitamin D deficiency?
Certain medical conditions can predispose an individual to be deficient in vitamin D levels. These include:
- Individuals suffering from conditions like Crohn’s disease, celiac disease or cystic fibrosis
- Individuals who have had gastric bypass surgery
- Obesity: Fat molecules grab vitamin D and do not release it for use in the body
- Very limited exposure to the sun
- A prolonged period of breastfeeding: Human breast milk contains a low amount of vitamin D
- A diet lacking enough vitamin D supplements (like vegan diets)
You may also be interested in: What do genes tell us about vitamin D requirements?
How does vitamin D deficiency affect your health?
Research suggests that vitamin D deficiency is linked to many serious disorders like:
- Lupus
- Multiple sclerosis
- Pre-menstrual syndrome
- Inflammatory bowel diseases
- Eczema
- Tooth and gum decay
- Alzheimer's
- Dementia
- Schizophrenia
- Depression
- Asthma
- Osteoporosis
- Rickets
- Cancer
- Erectile dysfunction
What are the best food sources of vitamin D?
Very few food items naturally contain vitamin D. Including them in your diet would greatly help alleviate vitamin D deficiency.
- Fishes like tuna, salmon, swordfish, herring, and sardines
- Milk & dairy products like eggs, yogurt and cheese and vegan alternatives like soy and almond milk
- Mushrooms
- Cod Liver Oil
Is vitamin D deficiency genetic?
Research has identified four genetic variants that are associated with vitamin D deficiency.
These genes are involved in metabolization and transportation of vitamin D in the body.
More such genetic variants inherited, the higher the risk for low vitamin D levels in the body.
Does your 23andme, Ancestry DNA, FTDNA raw data have VDR gene variant information?
| CHIP Version | VDR SNPs |
| 23andMe (Use your 23andme raw data to know your VDR Variant) | |
| v1 23andme | Present |
| v2 23andme | Present |
| v3 23andme | Present |
| v4 23andme | Present |
| V5 23andme (current chip) | Present |
| AncestryDNA (Use your ancestry DNA raw data to know your VDR Variant) | |
| v1 ancestry DNA | Present |
| V2 ancestry DNA (current chip) | Present |
| Family Tree DNA (Use your FTDNA raw data to know your VDR Variant) | |
| OmniExpress microarray chip | Present |
References
- https://www.ncbi.nlm.nih.gov/pubmed/16159929
- https://www.ncbi.nlm.nih.gov/pubmed/11684540
- https://www.ncbi.nlm.nih.gov/pubmed/15012617
- https://www.ncbi.nlm.nih.gov/pubmed/22681928
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5068478/
“Nutrigenetics, fitness genetics, health genetics are all nascent but rapidly growing areas within human genetics. The information provided herein is based on preliminary scientific studies and it is to be read and understood in that context.”
