Vitamin D is especially active in areas of the human genome related to autoimmune diseases, providing yet more evidence that the vitamin plays a critical role in regulating the immune system and protecting against certain diseases.
In a study published in the journal Genome Research, researchers from Oxford University mapped the human genome looking for clusters of vitamin D receptors — sites where the vitamin can bind to DNA, changing the expression of a gene. They found that these receptors were especially common in regions that have previously been linked to common autoimmune diseases, including Type 1 diabetes, multiple sclerosis and Crohn’s disease. Vitamin D receptors were also common in regions linked to colorectal cancer and leukemia.
The study shows how serious the effects of vitamin D deficiency can be, the researchers noted.
Scientists have long known that vitamin D plays an essential role in maintaining healthy teeth and bones, but only recently has the vitamin’s role in immune regulation started to become clear.
“The benefits of vitamin D include a reduction in the risk of colon polyps and prostate cancer, less coronary artery disease, and a decreased chance of developing type 1 diabetes, plus increased muscle strength and coordination, along with higher bone strength,” writes Phyllis A. Balch in her book Prescription for Nutritional Healing, 4th Edition.
The best source of vitamin D is exposure to sunlight. In only a fraction of the time it takes to burn, the body can produce up to 10,000 IU of the vitamin — as little as 15 minutes per day for light-skinned people and as much as three times that for people with much darker skin.
Sunscreen blocks the ultraviolet radiation that the body needs to synthesize vitamin D.