Vitamin D

Vitamin D is a fat-soluble vitamin that the body obtains from animal-derived foods, such as fish, liver, cheese and egg yolk, as well as vitamin D-fortified food items. This vitamin is also produced by our own body. Whenever UVB-B rays of sunlight strike the skin, cutaneous cholesterol is synthesized into vitamin D.

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Vitamin D is crucial for calcium absorption. Deficiency may hinder bone growth and health, including rickets in children and osteoporosis in older adults. Vitamin D is also involved in the immune system and inflammation processes. It has a possible role against cancer, heart disease, fractures and falls, autoimmune diseases, influenza, type-2 diabetes, and depression.

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Prevalence of Vitamin D deficiency is as high as 50% among some populations, especially in children and the elderly. Vitamin D deficiency is usually associated with limited sun exposure or vegan diet. Variations in the following genes are another risk factor for vitamin D deficiency:

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Gene: GROUP-SPECIFIC COMPONENT (GC), aka VITAMIN D-BINDING PROTEIN (DBP)

Genomic coordinates (GRCh38): 4:71,741,692-71,805,519

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GC protein a serum glycoprotein that binds to vitamin D metabolites and transports them to target organs.

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Gene: CYTOCHROME P450, SUBFAMILY IIR, POLYPEPTIDE 1 (CYP2R1)

Genomic coordinates (GRCh38): 11:14,877,435-14,898,912

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CYP2R1, a member of the CYP2 family encoding cytochrome P450 proteins, is a key vitamin D synthesis enzyme in the liver.

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Gene: 7-DEHYDROCHOLESTEROL REDUCTASE (DHCR7)

Genomic coordinates (GRCh38): 11:71,434,410-71,448,430

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DHCR7 encodes an enzyme that acts in the synthetic pathway of vitamin D3. 

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Gene: VITAMIN D RECEPTOR (VDR)

Genomic coordinates (GRCh38): 12:47,841,536-47,905,030

 

VDR encodes for the vitamin D receptor in tissues. 

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General recommendations: normally, a 15 minute exposure to strong sun radiation 3 times a week should be enough. Since radiation conditions and skin types differ, and some people have elevated risk for skin cancer, consult your doctor about the right amount of sun exposure for you.

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