Vitamin D and cancer survival – new results

Cancer Research UK does fund some vitamin D research. The results from one such piece, published in this month’s Journal of Investigative Dermatology, are in:

“UK guidance advising casual short exposures to UVB in summer sunlight … three times weekly for 6 weeks, while wearing T-shirt and shorts … SUBOPTIMAL vitamin D status is attained after a summer’s short (13  minutes) sunlight exposures to 35% skin surface area”

I trust Cancer Research UK will update their advice accordingly, so that we can all obtain an OPTIMAL vitamin D status

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Rhodes, L. E. et al. Recommended summer sunlight exposure levels can produce sufficient (>/=20 ng ml(-1)) but not the proposed optimal (>/=32 ng ml(-1)) 25(oh)d levels at uk latitudes. The Journal of investigative dermatology (2010). URL http://dx.doi.org/10.1038/jid.2009.417.

I’ll see what I can do ;-)

If someone is willing to put their hands up, then could I suggest a RCT of colon cancer prevention with high dosage D supplementation.

The IARC review of vitamin D concluded “results show evidence for an increased risk of colorectal cancer and colorectal adenoma with low serum 25-hydroxyvitamin D levels” and CRUK website states “vtamin [sic] D does somehow help to reduce the risk of bowel cancer”, which would suggest a more favourable consideration for any request.

Colon cancer is a very common cancer, which should help minimise the trial size.

Here’s a game that you might like to play:

Whenever a new genetic ‘breakthrough’ is announced, go to Google Scholar, type “vitamin D” and the name of the linked gene, enzyme, etc.

Almost everytime you’ll find a result comes back with evidence that VDRs (vitamin D receptors) are active in the discovery’s metabolic pathway.

Here are some to start you off – PARP, NOTCH, P53

I also found the statement “Vitamin Ds role in cancer prevention is not cut and dried” somewhat amusing. New oncology drugs get into clinical trials based on a few in vitro cell cultures and xenograft studies in mice. Both of these models have been shown to have little correlation with clinical activity but they continue to be used simply because nothing else better has been found, hardly, a “cut and dried’ situation.
However let me address Kevin Gellings question “would they fund a controlled study with vitamin D should it be proposed.’’ I propose the answer is a resounding “No” for the very same reasons they have not taken the initiative to start such a study. Present day oncology researchers have all built their careers on the genetic basis of cancer. This is the present ‘group think ‘ , cancer is a genetic disease and we will cure it by mapping out the genome of tumors, identifying the genetic mutations that drive the tumor and developing drugs that work against each of those mutations hence tailoring drug therapy to each individual patients tumors genetic profile. This strategy has produced next to nothing in terms of improving patient survival. Any claimed improvement in survival (minor as it is) is almost certainly due to early diagnosis and better standards of general medical support i.e. treatment of anemia and concurrent infections. To set up a study with vitamin D in cancer prevention/treatment and have it work would prove that the oncology community went down the wrong path which has been the basis of their whole career. Imagine the embarrassment of having ignored almost 30 years of increasing data on vitamin D (Garlands original proposal that vitamin D levels explained the difference is cancer rates at different latitudes was published in 1979).
In the US such a study is about to start. It is called the VITAL Study and is due to start 2010 in 20,000 patients. In this study subjects will receive placebo or vitamin D (2000IU) plus fish oil (1gm). It just so happens that fish oil contains Vitamin A, which has been shown to impair the absorption of Vitamin D and hence its effect. So in their wisdom, our experts have managed to come up with a trial design where vitamin D is combined with the one substance on planet earth that can impair its effect. To be fair the study is actually a four arm study so each substance will be examined alone, but why confound the question. We simply need a large study comparing vitamin D to placebo in cancer prevention. However most of the vitamin D experts would say that the extent of the data on vitamin D preventing cancer is now so extensive, that to conduct such a study is unethical. There is no known downside to correcting vitamin D deficiency. To expose people to placebo will answer an academic question but exposes that population to what many would consider an unnecessary and unethical risk. I for one will not be participating in the trial and will continue to take my 6000IU of vitamin D3 per day

Vitamin D’s role in cancer prevention may not be “cut and dried”, but there’s a lot of circumstantial evidence.

Ecological studies are conclusive – cancer is linked to latitude and race. Cohort and prospective studies are conclusive – cancer is linked to vitamin D (as the two studies above demonstrate). Laboratory experiments are conclusive – calcitriol (the active form of vitamin D) has many anti-cancer regulatory properties including propagation, differentiation, apoptosis and angiogenesis (e.g. research published this month shows that calcitriol suppresses aromatase in breast cancer – PMID 19906814).

Small RCTs have shown beneficial effects of vitamin D levels for colon, breast and prostate cancer (Garland et al. 2006). The one large RCT that has been conducted show a 77% all-cancer risk reduction (Lappe et al, 2007). This RCT has been criticised because, with results this good, mistakes must have been made.

There is one missing step – a large scale RCT that can confirm (or deny) these findings.

“We can usually only fund trials if we get high-quality research proposals for a specific project”.

So the ‘million pound question’ is, if someone was able to present such a proposal for a suitable large scale RCT, would Cancer Research UK fund it?

So what you are saying Kat, is that cancer research does not take the initiative to suggest a study and look for investigators interested in conducting the study but can only be passive and respond to requests for funding if someone else comes up with the idea. Progress tends to more dramatic when proactive steps are taken!

While the work you are funding with Professor Rhodes does appear interesting, I am curious to know why a randomised controlled trial of vitamin d supplementation vs placebo for cancer prevention is not being carried out?
Observational data suggests that a once per 6 months oral boost of vitamin d (60,000iu?) could significantly cut the rate of ca bowel, which is the 3rd most common cancer in the UK. Surely this is an obvious area for cancer UK funding?

The Canadian Cancer Society has been recommending that everyone take vitamin D to prevent cancer for over two years. If you would like to see the data that led to this go to http://www.vitaminD3world.com

Hi Kat,

The rate of melanoma is rising dramatically for indoor workers but not those who work outside (Cooke 1984 – http://www.ncbi.nlm.nih.gov/pubmed/6746119).

UVB creates vitamin D3 in the skin. Most is absorbed into the body, but some may be converted into an active form of the vitamin – calcitriol – which can kill melanoma cells.

Recent research from the US Food and Drug Agency (www.ncbi.nlm.nih.gov/pubmed/19155143) has shown that indoor workers are exposed to higher levels of UVA light.

So, by following SunSmart’s sun avoidance advice (“we recommend using sunscreens together with shade or clothing” = < 4% of available UVB light), we could be sitting at our desks without a tan that would protect us from UVA and without vitamin D3 in our skin which can kill cancerous melanoma cells.

The facts are:
– the full physiology of melanoma is not yet understood
– the SunSmart solution has not been scientifically proven

Hello Kat
Firstly no one is suggesting we go out into the sun and burn, but based on the multiple studies to data keeping your vitamin D levels has no down side. Those that live in sunny areas have levels of 70-90ngs/ml and in the UK you are lucky is your level is 20ng/ml. The Canadian Cancer Society have been recommending that everyone take vitamin D supplements for over two years unyet your organiziation remains silent and does not address the issue. Cancer reasearch is now funding Professor Rhodes who is a dermatologist. What about starting the prospective double blind trials on cancer prevention that everyone in the cancer industry states need to be done before we can start correcting a deficiency. These should have been done 20 years ago. There is now as much data on vitamin D preventing cancer as there was on smoking causing cancer-what are we waiting for!!!

> “We know that we all need a bit of sunshine in our lives”

After the success of the SunSmart campaign I suspect most people don’t know this.

The original SunSmart message was sun = bad (from SunSmart 2003 leaflet: ‘there is no such thing as a safe tan’, ‘the sun is most dangerous in the middle of the day’ and ‘apply sunscreen … before you go outside’). The current SunSmart campaign has been subtly (and silently) changed to allow for some sun exposure, but only in the shade (50% less UVB) and “together with” a sunscreen of SPF 15+ (93% less UVB).

> “vitamin D supplements .. cause harm if taken in large does without medical supervision”

The 2003 FSA advice is out-dated, based on the incorrect assumption that vitamin D2 and D3 are equivalent and was influenced by discredited research (www.vitamindcouncil.org/worst_science.shtml).

In the US, the NIH has updated its advice (ods.od.nih.gov/factsheets/vitamind.asp) and notes ‘substantially larger doses administered for a short time or periodically (e.g., 50,000 IU/week for 8 weeks) do not cause toxicity’

> “most people make more than enough vitamin D after a just a short time in the sun”

This is contrary to recent research that suggests that a majority of the population in the UK and the US do not have enough vitamin D.

And prospective studies suggest that in Scotland, because of sun strength, it is highly unlikely that even the most dedicated sun-worshipper in Scotland could make enough vitamin D by sun exposure alone.

> ” continually reviewing the scientific evidence”

CRUK has been keen to point out the flaws in current vitamin D research – as the saying goes “correlation does not show causation”. This is a noble (and maybe the proper) position to take, however, this approach has not been applied to its own advice. SunSmart has been based on a correlation between sunburn and melanoma (sun = sunburn, therefore sun = skin cancer), but where is the evidence showing causation? And, more importantly, where are the large-scale RCTs that show that the SunSmart solution – avoid the sun – reduces melanoma and does not have any “unintended consequences”?

It has been calculated that for every skin cancer death that SunSmart has prevented, 2000 deaths have been caused because of a lack of vitamin D (Lucas, R.M., et al., Estimating the global disease burden due to ultraviolet radiation exposure. Int J Epidemiol 2008).

The data on vitamin D playing a major role in cancer prevention has been evolving for 30 years and still all we hear is the need for further studies. How is it that organizations such as cancer research UK have still not conducted these studies or even started them. Folk who live in sunny areas have vitamin D levels of 50-70ng/ml. You are lucky if your levels of over 20 living in the UK. Correct your deficiency and worry about the clinical trials later.

As an ex cancer suffer, I recommend all who will listen to take 5,000 to 10,000IU of D a day. It is a pity I only read the literature AFTER I got cancer, otherwise I may have been able to avoid it.

If nothing else the reduced risk of infection from vitamin d will make the chemotherapy easier.

Those who have listened have been able to stop taking statins and blood pressure tablets as they no longer need them. They catch less colds and are much healthier. They are also less likely to burn in the sun.

People do not get enough vitamin d from casual sun exposure, otherwise why did recent research show that 70% of USA children were deficient. Neither is sun bathing any use as you cannot make vitamin d all year round. The risks from supplements is massively overstated in the none specialist literature, it has become an urban myth. See Vitamin D and Cancer Mini-Symposium: The Risk of Additional Vitamin D, REINHOLD VIETH, doi:10.1016/j.annepidem.2009.01.009, this presents data that shows that 10,000IU of d3 a day plus sun exposure does not lead to toxicity (most people need this amount to reach optimum levels).

The eatwell.gov website has failed to keep up with modern research and the levels recommended are stupidly low (400IU a day). With full body exposure at midday the body makes 10,000 to 20,000IU a day, Why would it make so much if it needed so little. The site says most people get enough vitamin d from food and sun which given the research published giving peoples vitamin d levels is also rubbish.