Vitamin D: Protecting against DNA damage

As readers may know, I believe one of the most important functions of vitamin D that has recently been discovered is vitamin D’s role in DNA repair. Failure to repair DNA often causes point mutations, like the ones seen in autism.
DNA repair is a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities such as oxidations from aerobic metabolism, and environmental factors such as radiation, cause DNA damage. This results in up to a million individual DNA lesions per cell per day.
Many of these lesions cause structural damage to the DNA molecule and can alter or eliminate the cell’s ability to copy the gene that the affected DNA codes. Other lesions induce potentially harmful mutations in the cell’s genome, which affect the survival of its daughter cells after it undergoes division and multiplications. Therefore, the DNA repair process is constantly active as it responds to damage in the DNA structure. When normal repair processes fail, and when normal cell death (apoptosis) of damaged cells does not occur, irreparable cellular damage may occur.
Recently, Dr H Dorota Halicka and colleagues of New York Medical College, reviewed the literature on the role of vitamin D in DNA repair and conducted an experiment in colon cells to see if activated vitamin D reduced DNA damage.
Halicka HD, Zhao H, Li J, Traganos F, Studzinski GP, Darzynkiewicz Z. Attenuation of constitutive DNA damage signaling by 1,25-dihydroxyvitamin D3. Aging (Albany NY). 2012 Apr;4(4):270-8.
The authors report the following:
  1. Three recent studies using genes profiling “revealed that the DNA repair genes are among a multitude of genes whose transcription is induced by activated vitamin D.”
  2. “There is ample evidence that activated vitamin D provides protection against oxidative DNA damage.”
  3. Activated vitamin D directly upregulates a key antioxidant, thioredoxin reductase.
  4. “Another antioxidant protein induced by activated vitamin D is superoxide dismutase.”
  5. The authors found that activated vitamin D lessened the DNA damage in colon cells.
As readers know, DNA repair is essential for the survival of the species. Such repair also helps ensure that one lives up to their genetically allotted time in this world, instead of dying young from one of the hundreds of diseases enhanced by faulty DNA repair.
Readers are also aware that the most replicated genetic finding in autism is evidence of point mutations, a telltale sign of faulty DNA repair. This is one of the reasons I think the autism epidemic has been triggered by gestational and early childhood vitamin D deficiencies. The lack of vitamin D to repair DNA may be causing the point mutations so often seen in autism.