Vitamin D Reduces Cancer Deaths
There’s good news for those of you who have taken the proactive step to make sure your vitamin D level is optimized. Several recent studies demonstrate vitamin D can have a significantly beneficial impact on your cancer risk, both in terms of preventing cancer and in the treatment of cancer.
Vitamin D Reduces Cancer Mortality
In the first of these studies,1,2 which included 25,871 patients, vitamin D supplementation was found to reduce the risk for metastatic cancer and death by 17%. The risk was reduced by as much as 38% among those who also maintained a healthy weight.
This was a really poorly done study as they only gave participants 2,000 IUs a day and never measured their blood levels. Had there been no improvement, I would not have been surprised, but the fact is it still reduced metastatic cancer and death by 17%, and they found significant benefit among those who were not obese.
This is pretty extraordinary but not as good as epidemiological studies that show a 50% to even 78% reduction in vitamin D sufficient people, as suggested in a study further below. That said, UPI reported the results saying:3
“The benefits of vitamin D3 in limiting metastases — or disease spread to other organs — and severity was seen across all cancers, and was particularly prominent among study participants who maintained a healthy weight …
‘The primary message [of our study] is that vitamin D may reduce the chance of developing metastatic or fatal cancer among adults without a diagnosis of cancer,’ study co-author Dr. Paulette Chandler told UPI.”
The study, published in JAMA Network Open, is a secondary analysis of the VITAL Study4 which, in part, sought to determine whether taking 2,000 IUs of vitamin D per day would reduce the risk of cancer, heart disease or stroke in people who did not have a prior history of these diseases.
The VITAL study itself, which followed patients for an average of 5.3 years, found no statistical difference in overall cancer rates among those who took vitamin D3, but there was a reduction in cancer-related deaths, which is what prompted this secondary analysis.
Obesity May Inhibit Vitamin D’s Benefits
The fact that patients with a healthy weight derived a much greater benefit — a 38% reduced risk for metastatic cancer and death compared to 17% overall — suggests your body weight may play a significant role in whether vitamin D supplementation will provide you with the anticancer benefits you seek.
According to study co-author Dr. Paulette Chandler, assistant professor of medicine at Brigham and Women’s Hospital in Boston, “Our study highlights that obesity may confer resistance to vitamin D effects.”5
There may be something to that. Research6 published in 2010 found that dietary fructose inhibits intestinal calcium absorption, thereby inducing vitamin D insufficiency in people with chronic kidney disease.
That said, vitamin D tends to be lower in obese people in general, for the fact that it’s a fat-soluble nutrient and when you’re obese, the vitamin D ends up being “volumetrically diluted.” As explained in the paper “Vitamin D in Obesity,” published in 2017:7
“Serum vitamin D is lower in obese people; it is important to understand the mechanism of this effect and whether it indicates clinically significant deficiency … Vitamin D is fat soluble, and distributed into fat, muscle, liver, and serum.
All of these compartments are increased in volume in obesity, so the lower vitamin D likely reflects a volumetric dilution effect and whole body stores of vitamin D may be adequate … Obese people need higher loading doses of vitamin D to achieve the same serum 25-hydroxyvitamin D as normal weight.”
While that particular paper stresses that lower vitamin D in obese individuals might not mean that they’re deficient, others disagree. For example, one study8,9 found that for every 10% increase in body-mass index, there’s a 4.2% reduction in blood levels of vitamin D. According to the authors of that particular study, obesity may in fact be a causal factor in the development of vitamin D deficiency.10
Article from LewRockwell