December 17, 2012

196 Vitamin D and Cancer [17 Dec 2012]

I first wrote on this topic 3 years ago in Column #42, 14 December 2009. In that column I reviewed a study estimating that raising vitamin D levels could prevent 58,000 cases of breast cancer and 49,000 cases of colorectal cancer in the US and Canada each year and prevent 75% of the deaths from these two cancers alone. Another researcher listed 16 different cancers that vitamin D has been shown to reduce including pancreatic, lung, ovarian, prostate and skin cancers, and estimated that 30% of cancer deaths worldwide could be prevented with higher levels of vitamin D.

Professor John White and associates at McGill have recently discovered a possible mechanism for vitamin D’s protective effect on cancer. Vitamin D suppresses cMYC, an RNA protein that causes cell proliferation and is known to be more active in cancer cells (note: estrogens increase cMYC activity). It also enhances the expression of MXD1 a protein that is antagonistic to cMYC.

White was quoted in a report on the study by Nathan Gray in
“Our results show that vitamin D puts the brakes on cMYC function, suggesting that it may slow the progression of cells from premalignant to malignant states and keep their proliferation in check… We hope that our research will encourage people to maintain adequate vitamin D supplementation and will stimulate the development of large, well-controlled cancer chemoprevention trials to test the effects of adequate supplementation.”

So what is adequate supplementation? Some vitamin D researchers consider the optimal range to be 50 – 65 ng/ml with the most protection at the higher end of the range. Cancer treatment would fall in the 65 – 90 range. Levels over 100 are now considered high. To achieve the optimal range, the current recommendation for supplementation is 35 IU per pound of body weight. At 200 lbs I would need 7,000 IU per day. This value would vary with season, sun exposure and skin color.

For more information on this or other natural health topics, stop in and talk to Stan; for medical advice consult your licensed health practitioner.

1 comment:

  1. Remember that only D3 should be used in supplementation. A study from New Zealand published in July 2012 found that D2 did not increase total D as much as D3 and even caused a greater loss over winter in the (active) D3 levels than did the placebo. If your doctor prescribes D2 (some still do!) give him/her this reference.
    Logan VF, Gray AR, Peddie MC, Harper MJ, Houghton LA. Long-term vitamin D3 supplementation is more effective than vitamin D2 in maintaining serum 25-hydroxyvitamin D status over the winter months. Br J Nutr. 2012 Jul 11:1-7.