Vitamin D and Cancer Risk?

Written by Dr. Steve Chaney on . Posted in Vitamin D and Cancer Risk

Does Vitamin D Reduce Cancer Risk?

Author: Dr. Stephen Chaney

 

vitamin d and cancer riskThe relationship between vitamin D and cancer risk is controversial. Some studies suggest that vitamin D reduces cancer risk. In those studies, the risk reduction was strongest for colon cancer, lung cancer, and breast cancer. However, other studies have found no association between vitamin D status and cancer risk.

Most previous studies have been conducted in European and American populations. Very few of the studies have been done in Asian populations. So, the authors of the current study (S. Budhathoki et al, BMJ 2018; 360:k671, doi: 10.1136/bmj.k671 ) focused their attention on the Japanese population.

How Was The Study Done?

vitamin d and cancer risk studyThe data for this study were drawn from the much larger Japanese Public Health Center (JPHC) Study. THE JPHC Study is an ongoing study investigating the role of lifestyle and other factors on the risk of cancer and other diseases. The study began in 1990 and enrolled 140, 420 participants aged 40-59.

All participants in the JPHC study filled out a detailed food frequency questionnaire at the time of entry into the study. A subset of participants also donated blood upon entry into the study for determination of 25-hydroxyvitamin D levels (the most reliable measurement of vitamin D status). It is this subset of participants who formed the basis of the current study.

There were 33,736 participants in this study. Based on plasma 25-hydroxyvitamin D levels at entry into the study, the participants were divided into four groups of around 1000 participants.

  • Group 1 had a median serum 25-hydroxyvitamin D level of 36.9 nmol/L.
  • Group 2 had a median serum 25-hydroxyvitamin D level 48.4 nmol/L.
  • Group 3 had a median serum 25-hydroxyvitamin D level of 56.9 nmol/L.
  • Group 4 had a median serum 25-hydroxyvitamin D level of 72.6 nmol/L.

For reference, the NIH considers < 30 nmol/L to be deficient, 30 to < 50 nmol/L to be insufficient for bone and overall health, > 50 nmol/L to be sufficient, and > 150 nmol/L to be potentially associated with adverse effects. By these criteria, group 1 had insufficient serum levels of 25-hydroxyvitamin D, group 2 was borderline, and groups 3 and 4 had sufficient serum levels of 25-hydroxyvitamin D.

The participants were followed for a total of 19 years. During this time 3301 participants developed cancer. The cancer incidence in groups 2, 3 and 4 were compared to the cancer incidence in group 1 to determine the effect of vitamin D status on cancer risk.

 

Vitamin D and Cancer Risk

 

vitamin d and cancer risk study resultsThe results of the Vitamin D and cancer risk study were:

  • Vitamin D reduced total cancer risk by up to 25%.
  • Vitamin D reduced the risk of liver cancer by up to 55%.
  • Vitamin D reduced the risk of pre-menopausal breast cancer by up to 44%.
  • There was a trend towards reduction of colon, liver, and prostate cancer by vitamin D, but the results did not quite reach significance.
  • There were too few cases for most other cancers to assess whether vitamin D status had any effect.
  • Risk reduction was not linear. Except for liver cancer, risk reduction for group 4 (72.6 nmol/L) was not greater than the risk reduction for group 3 (56.9 nmol/L). The significance of this observation will be discussed below.

The authors concluded: “Our findings support the hypothesis that vitamin D may confer protection against cancer. Nevertheless, the lower risk associated with higher circulating vitamin D concentrations seemed to show a ceiling effect, which may suggest that although maintaining an optimal 25-hydroxyvitamin D concentration is important for prevention of cancer, having a concentration beyond this optimal level may provide no further benefit.”

 

Why Is The Association of Vitamin D And Cancer Risk So Confusing?

 

vitamin d and cancer risk confusionSo why do some studies demonstrate confusing data on Vitamin D and cancer risk?  The “ceiling effect” mentioned by the authors of this study may explain much of the variation in results from previous trials. As I say in my upcoming book, “Slaying The Supplement Myths” , supplementation is most likely to be effective when the subjects are deficient in that nutrient at the beginning of the study. If they are starting with adequate levels of the nutrient, supplementation is unlikely to provide additional benefit.

While that statement seems to be obvious, many previous studies have ignored the beginning nutritional status. Some have not measured 25-hydroxyvitamin D levels at the beginning of the study. Others have measured starting 25-hydroxyvitamin levels but have not considered the starting levels in interpretation of their data.

Group 1 in the current study clearly had inadequate 25-hydroxyvitamin D levels. That may be why the groups with sufficient 25-hydroxyvitamin D levels showed a reduction in risk. The low baseline 25-hydroxyvitamin D is logical because most of Japan lies north of the United States, so sun exposure is less. In addition, the authors stated that food fortification and supplementation with vitamin D is much less in Japan than the US. In contrast, the baseline 25-hydroxyvitamin D status in many US studies is significantly higher.

The authors did a thorough analysis of previous studies. In general, studies with a low baseline level of 25-hydroxyvitamin D showed a reduction in cancer risk by vitamin D. Studies with a higher baseline level of 25-hydroxyvitamin D showed no effect.

This analysis does not permit a definitive conclusion, but it clearly defines how future studies should be designed. Simply put, to reliably test whether vitamin D reduces cancer risk, the experiment must be designed in such a way that the baseline 25-hydroxyvitamin D level is in the inadequate range. Otherwise, there is no reason to expect that higher levels of 25-hydroxyvitamin D will confer any benefit.

 

The Bottom Line:

 

A recent study looked at the effect of vitamin D status (serum 25-hydroxyvitaminD levels) on cancer risk. The study reported:

  • Vitamin D reduced total cancer risk by up to 25%.
  • Vitamin D reduced the risk of liver cancer by up to 55%.
  • Vitamin D reduced the risk of pre-menopausal breast cancer by up to 44%.
  • There was a trend towards reduction of colon, liver, and prostate cancer by vitamin D, but the results did not quite reach significance.
  • There were too few cases for most other cancers to assess whether vitamin D status had any effect.
  • Risk reduction was not linear. Except for liver cancer, risk reduction for group 4 (72.6 nmol/L) was not greater than the risk reduction for group 3 (56.9 nmol/L).

The authors concluded: “Our findings support the hypothesis that vitamin D may confer protection against cancer. Nevertheless, the lower risk associated with higher circulating vitamin D concentrations seemed to show a ceiling effect, which may suggest that although maintaining an optimal 25-hydroxyvitamin D concentration is important for prevention of cancer, having a concentration beyond this optimal level may provide no further benefit.”

The “ceiling effect” mentioned by the authors of this study may explain much of the variation in results from previous trials.

For more details, read the article above:

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

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Comments (4)

  • Kathleen-Marie

    |

    It’s important if we are taking a calcium supplement to be sure we are also getting adequate vitamin D from diet (mushrooms, eggs, fish), sunshine on the exposed skin midday in the summer, or our D3 supplementation. Especially for diets high in vitamin A, D is important too. All possibly affecting the cancer and disease prevention quality of circulating D2/3 in the bloodstream. It’s important to remember that vitamin D is a hormone precursor, or has hormone like affects on metabolism in general as well. In the animal world — reindeer moving North due to hotter temperatures (which means more suffocating flies in their nostrils), the reindeer are beginning to suffer from D deficiencies, even getting rickets and not being able to stand up well as babies. Wise vets and Laplanders have been putting a lot of lichen (which is also what our birds eat in the winter as source for D supplementation) in reindeer feeding areas. It’s so important for good immune function! I notice backyard birds eating lichen on rainy days perching on fallen tree branches around my feeders. Chimpanzes and other research and zoo animals also need D supplementation in their “chow” feed, along with fresh veggies and roots, to keep well and happier.

    Reply

  • Mary Butler

    |

    It asked me if chrome could access all of my files etc and I said no…so it didn’t download.

    Reply

  • Laura Nokes Lang

    |

    Thank you for letting us know the good news about eggs. I have always enjoyed eggs and usually have at least one a day. Now I know I’m not killing myself doing that, I feel better.

    Reply

  • Caroline

    |

    Dr., unfortunately I have seen women young and over age 55 with super low BP and that is dangerous. I chew on two REAL licorice pieces on the days my BP is too low and I am over 80 and I get back my energy and brain working well. I do take the OmegaGuard and sell a lot of it, thank goodness. But then I still have some trust left in Shaklee.

    Reply

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Latest Article

Groin Pain Relief

Posted April 16, 2019 by Dr. Steve Chaney

What Is The Pectineus Muscle And Why Is It Important?

Author: Julie Donnelly, LMT –The Pain Relief Expert

Editor: Dr. Steve Chaney

 

Spring Is In The Air

spring floridaI remember as a child we sang “Though April showers may come your way…they bring the flowers that bloom in May…”

Of course, here in Florida we are blessed with flowers all year, but there’s still a lovely feeling that happens in Spring.  It’s still cool enough most days to go out running, and the humidity is still low.  Traffic will soon be easing up as our friends from the north start their trek back home, and daylight savings time is giving us more time to get to the beach for sunset.  Lovely!

Fun Facts About Spring….

  • The earliest known use of the term “spring cleaning” was in 1857
  • The word “spring” has been used for the season since the 16th century
  • The first day of spring is called the vernal equinox
  • On the first day of spring, the sunrise and sunset are about 12 hours apart everywhere on earth
  • Spring fever isn’t just a saying. Experts say the body changes due to the temperature and can cause an upset in your health.
  • The actual start of spring varies from March 19th to the 21st, but it is commonly celebrated on the 21st.

Do you like to garden?  Now is the perfect time to get your gardens planted so you’ll have home grown veggies for the entire summer.  For me, it’s also a great time to do some spring cleaning and get the house in order before the summer closes all the windows and the air conditioning becomes our indoor relief.

But these activities can also cause a strain on muscles, so don’t forget to take care of yourself. If you put too much strain on muscles you haven’t used all winter, you can develop problems and need groin pain relief.

 

A Tiny Muscle Can Cause Groin Pain

groin pain relief pectineusLately I’ve had several clients come in because of groin pain that has their medical practitioners stumped.  Their symptoms are varied, but most complain that it feels like they hit their pubic bone with a rubber mallet.  Ouch!

One client loves to ride her horse, but the pain had prevented that for several weeks. Another was considering selling the motorcycle that she and her husband love because she just can’t sit on it anymore.

Several years ago, I had a male client tell me that he had this same pain and he was told it could be his prostrate causing the issue.  Fortunately, that wasn’t he problem at all.

The muscle that caused all these problems, and a lot more, is the Pectineus.

The Pectineus muscle originates on your pubic bone and inserts into the very top of your inner thigh bone (femur).

You can see the Pectineus and surrounding muscles more clearly by going to https://en.wikipedia.org/wiki/Pectineus_muscle

Most muscles have more than one function, and this is true for the Pectineus.  The function we’ll look at today is called adduction.  It brings your leg in toward midline.  If you think of a soccer player kicking the ball with the inside of his ankle, it was the Pectineus that helped draw his leg in so he could do the shot.

Each of my clients had pain while trying to bring their leg out so they could sit on their horse, or on their motorcycle.  The tight muscle was pulling on their pubic bone and causing a severe strain.

This muscle is easier to have someone else treat it for you because of its location but give it a try and see if you can locate & treat it yourself.

 

Groin Pain Relief

groin pain relief treatmentThe picture to the left is showing an athlete self-treating her adductors.  These muscles, and the Pectineus muscle, all originate at the same point on the pubic bone.  The picture is showing her massaging the middle of the adductors.

To reach the Pectineus, move the ball all the way up to the crease in your leg.  You can do the treatment with a ball, but because of the size of the muscle and its location, it’s easier to do it with your fingertips.

Sit as this athlete is sitting, and even bring your opposite leg up so your foot is flat on the floor.  For example, in this picture, the athlete would bring her right leg up so her right foot is on the floor, and then lean a bit further onto her left hip.  That opens up the area so she can reach a bit easier into the muscle while using her fingertips.

Press into the muscle, being careful to feel for a pulse, and moving if you feel one.  If the Pectineus is in spasm, you’ll know it immediately when you press on it.  If it’s not in spasm, you won’t be able to find it at all.

Remember to stay within your pain tolerance level, this isn’t a “no pain, no gain” situation.  Never go deeper than what feels tender, but not so much that you want to faint. Hold the pressure for 15 seconds. Then let up on the pressure, but keep your fingers in the same place.

Repeat this movement several times. Each time it will hurt less, and eventually it won’t hurt at all.  That’s when the muscle has completely released, and you will have relief from the pain.

It’s as simple as that!

Why stay in pain when it’s so easy to find the muscular source of the problem and eliminate it?

calf cramps remedy bookTreat Yourself to Pain-Free Living (https://julstromethod.com/product/treat-yourself-to-pain-free-living-hardcopy/). It is filled with over 100 pictures and descriptions proven to show you how to find and self-treat muscle spasms from head to foot!

Join the 1000’s of people worldwide who have discovered that tight muscles were the true source of pains they thought were from arthritis, fibromyalgia, and other serious conditions.  You have nothing to lose, and everything to gain by releasing tight muscles.

Treat Yourself to Pain-Free Living is your step-by-step guide to pain relief!

 

Wishing you well,

 

Julie Donnelly

 

These statements have not been evaluated by the Food and Drug Administration. This information is not intended to diagnose, treat, cure or prevent any disease.

 

julie donnellyAbout The Author

Julie Donnelly is a Deep Muscle Massage Therapist with 20 years of experience specializing in the treatment of chronic joint pain and sports injuries. She has worked extensively with elite athletes and patients who have been unsuccessful at finding relief through the more conventional therapies.

She has been widely published, both on – and off – line, in magazines, newsletters, and newspapers around the country. She is also often chosen to speak at national conventions, medical schools, and health facilities nationwide.

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