Why is it that vitamin D deficiency can manifest in so many different ways in different people? One big reason is something called vitamin D receptor (VDR) genotypes , the variation in the receptor for vitamin D.
It means that vitamin D deficiency sustained over many years in:
Peter yields prostate cancer
Paul yields coronary heart disease and diabetes
Mary yields osteoporosis and knee arthritis .
Same deficiency, different diseases.
VDR genotype-determined susceptibility to numerous conditions have been identified, including Graves' thyroiditis, osteoporosis and related bone demineralization diseases, prostate cancer (Fok1 ffI genotype), ovarian cancer, rheumatoid arthritis, breast cancer (Fok1 ff), birth weight of newborns, melanoma and non-melanoma skin cancers, insulin resistance and metabolic syndrome, susceptibility to type I diabetes, Crohn's disease, and neurological or musculoskeletal deterioration with aging that leads to falls, respiratory infections, kidney cancer, even periodontal disease.
Why is it that the dose of vitamin D necessary to reach a specific level differs so widely from one person to the next? VDR genotype, again. Variation in blood levels of 25-hydroxy vitamin D from a specific dose of vitamin D can vary three-fold , as shown by a University of Toronto study. In other words, a dose of 4000 units per day may yield a 25-hydroxy vitamin D blood level of 30 ng/ml in Mary, 60 ng/ml in Paul, and 90 ng/ml in Pete--same dose, different blood levels.
Should we all run out and get our VDR genotypes assessed? So far the data have not progressed far enough to tell us. If, for instance, you prove to have the high-risk Fok1 ff genotype, would you do anything different? Would vitamin D supplementation be conducted any differently? I don't believe so.
Virtually all of us should be supplementing vitamin D at a dose that generates healthy blood levels, regardless of VDR genotype. For those of us following the Track Your Plaque program for coronary plaque control and reversal, that means maintaining serum 25-hydroxy vitamin D levels between 60-70 ng/ml.
As the fascinating research behind VDR genotype susceptibility to disease unfolds, perhaps it will suggest that specific genotypes be somehow managed differently. Until then, take your vitamin D.