Vitamin D

Vitamin D is one hot topic these days, and it’s easy to get carried away with the enthusiasm. What we know about vitamin D and cancer prevention is this: we’re not sure. The studies that have been done looking at an association of vitamin D levels and cancer incidence have been mixed with regard to whether or not vitamin D is associated with a lower risk of cancer. I stress the word “association” here. We really don’t know if there is any causal relationship between vitamin D and cancer incidence. People who have normal vitamin D levels or who are taking vitamin D supplements may have other lifestyle factors that contribute to their overall good health. A randomized controlled clinical trial would be the gold standard to establish a causal relationship and we don’t have one yet. I recommend that you have your vitamin D level checked by your primary care physician and I think it is reasonable for most people to take a vitamin D supplement. Vitamin D is one hot topic these days, and it’s easy to get carried away with the enthusiasm. What we know about vitamin D and cancer prevention is this: we’re not sure. The studies that have been done looking at an association of vitamin D levels and cancer incidence have been mixed with regard to whether or not vitamin D is associated with a lower risk of cancer. I stress the word “association” here. We really don’t know if there is any causal relationship between vitamin D and cancer incidence. People who have normal vitamin D levels or who are taking vitamin D supplements may have other lifestyle factors that contribute to their overall good health. A randomized controlled clinical trial would be the gold standard to establish a causal relationship and we don’t have one yet. I recommend that you have your vitamin D level checked by your primary care physician and I think it is reasonable for most people to take a vitamin D supplement.

As I discuss in detail in my evidence-based book, A Cancer Prevention Guide for the Human Race (http://www.amazon.com/Cancer-Prevention-Guide-Human-Race/dp/1608446913), the overwhelming majority of disease prevention research, including cancer prevention research, is based upon low-level types of research, including survey-based public health studies and retrospective clinical studies. While these methods of research are rather quick and inexpensive to perform, the data that they produce is highly prone to various forms of bias. That is to say, their conclusions are often not highly accurate. On the other hand, prospective, randomized, placebo-controlled clinical research trials, when performed properly, provide the highest level of research evidence available. However, because this type of research is so demanding, and so expensive to perform, very few cancer prevention studies are performed using this high-level approach. With this in mind, it’s important to acknowledge that the vast majority of research on Vitamin D (http://www.cancercenter.com/cancer-center-news/news/vitamin-D-deficiency.cfm) as a cancer prevention agent is based upon methods that produce rather weak (and often contradictory) data. However, among all of the known vitamins, it is fair to say that only Vitamin D is still a reasonable contender as a potential cancer prevention agent, and particularly for people with low levels of this vitamin in their blood. Specifically, based upon available research data, Vitamin D appears to be potentially most effective as a prevention agent for colorectal cancer, with most studies suggesting a 25 to 30 percent reduction in the risk (http://www.doctorwascher.com/vitamin-d/vitamin-d-significantly-reduces-colorectal-cancer-risk.html) of colorectal cancer in patients who take Vitamin D supplements. In terms of recommending a daily dose for Vitamin D supplementation, there is no consensus as to how much Vitamin D should be taken as a supplement, although healthy patients can usually tolerate 1,000 to 3,000 IU per day without serious side effects. However, unfortunately, I cannot make specific recommendations regarding the optimal amount of daily Vitamin D intake at this time. Moreover, Vitamin D can be toxic when taken in high doses, and can lead to kidney stones, kidney failure, calcifications in the soft tissues of the body, GI tract ulcers, and other serious health problems. Therefore, if you are considering the addition of daily Vitamin D supplements as part of a cancer prevention lifestyle (as I discuss in my book), I recommend that you first discuss this with your personal physician. I would also recommend routine testing of your Vitamin D levels, to reduce the risk of Vitamin D toxicity. As I discuss in detail in my evidence-based book, A Cancer Prevention Guide for the Human Race (http://www.amazon.com/Cancer-Prevention-Guide-Human-Race/dp/1608446913), the overwhelming majority of disease prevention research, including cancer prevention research, is based upon low-level types of research, including survey-based public health studies and retrospective clinical studies. While these methods of research are rather quick and inexpensive to perform, the data that they produce is highly prone to various forms of bias. That is to say, their conclusions are often not highly accurate. On the other hand, prospective, randomized, placebo-controlled clinical research trials, when performed properly, provide the highest level of research evidence available. However, because this type of research is so demanding, and so expensive to perform, very few cancer prevention studies are performed using this high-level approach. With this in mind, it’s important to acknowledge that the vast majority of research on Vitamin D (http://www.cancercenter.com/cancer-center-news/news/vitamin-D-deficiency.cfm) as a cancer prevention agent is based upon methods that produce rather weak (and often contradictory) data. However, among all of the known vitamins, it is fair to say that only Vitamin D is still a reasonable contender as a potential cancer prevention agent, and particularly for people with low levels of this vitamin in their blood. Specifically, based upon available research data, Vitamin D appears to be potentially most effective as a prevention agent for colorectal cancer, with most studies suggesting a 25 to 30 percent reduction in the risk (http://www.doctorwascher.com/vitamin-d/vitamin-d-significantly-reduces-colorectal-cancer-risk.html) of colorectal cancer in patients who take Vitamin D supplements. In terms of recommending a daily dose for Vitamin D supplementation, there is no consensus as to how much Vitamin D should be taken as a supplement, although healthy patients can usually tolerate 1,000 to 3,000 IU per day without serious side effects. However, unfortunately, I cannot make specific recommendations regarding the optimal amount of daily Vitamin D intake at this time. Moreover, Vitamin D can be toxic when taken in high doses, and can lead to kidney stones, kidney failure, calcifications in the soft tissues of the body, GI tract ulcers, and other serious health problems. Therefore, if you are considering the addition of daily Vitamin D supplements as part of a cancer prevention lifestyle (as I discuss in my book), I recommend that you first discuss this with your personal physician. I would also recommend routine testing of your Vitamin D levels, to reduce the risk of Vitamin D toxicity.

I think this is an artificial distinction. We either have evidence, or we do not. Or we have weak versus strong evidence. I evaluate all interventions using the same standards. Nutrition is clearly an important component of health and we know that in general a low-fat, calorie-restricted diet, is healthier in myriad ways than another. However, the evidence that any particular component of the diet, or supplement, can prevent or treat illness is weak to non-existent. This limits our ability to endorse any specific recommendation. I think this is an artificial distinction. We either have evidence, or we do not. Or we have weak versus strong evidence. I evaluate all interventions using the same standards. Nutrition is clearly an important component of health and we know that in general a low-fat, calorie-restricted diet, is healthier in myriad ways than another. However, the evidence that any particular component of the diet, or supplement, can prevent or treat illness is weak to non-existent. This limits our ability to endorse any specific recommendation.