| |
Director's Letter
Carole Baggerly
Director, GrassrootsHealth
There has been so much in the media lately about vitamin D being ineffective. It is hard when you are the only one on the mountain top holding the flag, and the wind is blowing against you trying to knock you off. Do you ever feel like that?
I don't. I feel like that flag is stuck so deep in the mountaintop, that I don't need to brace it. There is so much evidence and research that just needs to be analyzed by serum level, that just needs an explanation.
Every time we look at a study that shows vitamin D is ineffective there is a reason. Bolus dosing, too low of dosing, too short of a time, co-nutrients weren't optimized, etc... It is usually glaring and can be found within just the abstract.
We hope you are learning to recognize the signs. You are learning to read through the headlines and be able to respond. We know you are holding a flag in your own community, your own workplace, your own family - and we hope these newsletters give you more information to cement that flag into the ground.
Onwards!
Carole Baggerly
Director, GrassrootsHealth
A Public Health Promotion & Research Organization
Moving Research into Practice NOW!
|
Vitamin D and Calcium Supplementation Decreases Cancer Risk in Older Women
Vitamin D and Calcium Supplementation Decreases Cancer Risk in Older Women
Joan Lappe, PhD, RN, FAAN
Professor
Associate Dean for Research
Beirne Endowed Chair in Nursing
College of Nursing, Creighton University
American Public Health Association Annual Meeting & Expo
November 1, 2016
Why did they do this study?
40% of the US population will develop cancer in their lifetime. This is not only a major impact to quality of life, but also costs billions of dollars to treat, an estimated $156 billion by 2020.
There are many epidemiological studies that have shown a correlation of certain cancers with latitude, which can then be associated with vitamin D levels. Many scientists have even worked out how adequate vitamin D could be a deterrent to cancer at the cellular level.
In addition, as the population has moved indoors and sun avoidance has been practiced, it has been noted that low vitamin D status is widespread.
Could something as simple as vitamin D and calcium supplementation reduce risk?
What was the study?
The study was a replication of a previous study, published in 2007. This study used more women and a slightly higher vitamin D amount (2000 IU/day instead of 1100 IU/day).
The 2007 study showed a 77% reduction in all non-skin cancers in the treatment group (1100 IU vitamin D and 1500 mg calcium/day). In this study cancer was a secondary outcome - so it was important to do another study with cancer as the primary outcome.
Who was allowed to participate in the new study?
Postmenopausal women 55 years of age and older, living independently, from a rural population in Nebraska, with a few exclusions.
2303 participants were assigned randomly to one of two groups. The treatment arm took 1 vitamin D (2000 IU capsule) once a day and calcium carbonate (500 mg/tablet) three times a day. The placebo group had identical placebo pills. Participants in both groups were allowed to take vitamin D (up to 800 IU/day) and calcium (up to 1500 mg/day).
At the beginning of the study, the mean age was 65 years old, and mean vitamin D intake was about 800 IU/day. Their mean vitamin D level was 33 ng/ml, which is relatively high compared to the general US population. (In the 2007 study, the mean was 28 ng/ml.)
What were the results?
After 4 years, 2064 women completed the study. New diagnoses of invasive or in situ cancer were confirmed by pathology reports in 86 subjects (34 in the treatment group, 52 in the placebo group), after excluding any diagnoses during the 1st year.
They excluded cases in the 1st year because it takes some time for vitamin D levels to rise and also it takes a little while for vitamin D to affect cancer formation. This was also noted in the 2007 study - vitamin D levels had an effect on cancer after the first year. In this study, visit 3 corresponded with 1 year of treatment and a table of vitamin D levels shows that the placebo group still had a mean of around 33 ng/ml (31.6 ng/ml), while the treatment group had a mean vitamin D level of 44 ng/ml.
For the remainder of the study the two groups stayed about the same with their vitamin D levels.
Breast cancer was the type of cancer most commonly found, accounting for more than a third of all cancers in both the treatment and placebo groups.
Charts and Percentages
The graph below shows an analysis by treatment group. This graph includes all 4 years of data, but notice how the two groups have virtually the same plot throughout year 1.
When including the year one data, the treatment group had a 30% reduction in all cancers, with a statistical significance, P-value, of .06. When excluding the year one data, the treatment group had a 35% reduction in all cancers, with a P-value, of .047.
The P-value is a probability, it is a percentage. In the first calculation the P-value was .06, which means that there is a 6% chance that this result (30% reduction in cancer in the vitamin D + calcium group) was due to chance - not the actual treatment. In a different wording, that means you are 94% sure it was NOT chance! The scientific community has agreed that P=.05 or less is an accepted amount for study results to have "significance" and anything higher than P=.05 is "not statistically significant." There is no middle ground, it is black or white.
Note the second calculation had "significance" with a P-value of .047, which means statistics showed that there is a 95.03% chance that the treatment (vitamin D + calcium) was responsible for the 35% lower cancer risk in years 2-4.
By vitamin D level
We find a higher significance level (P-value) when analyzing by serum level. This was also true of the 2007 study. Of special note is the very clear downward trend of the risk.
This analysis concluded that when compared with a vitamin D level of 30 ng/ml, participants with vitamin D level of 55 ng/ml were 35% less likely to get cancer (P=.03). This means that statistics found a 97% probability that the treatment (vitamin D levels greater than or equal to 55 ng/ml) was responsible for a 35% lower risk of cancer.
Adding other data points
GrassrootsHealth combined data for women 55 and older from the GrassrootsHealth D*action cohort (N = 1,135, median serum level = 48 ng/ml) and the cohort from Lappe's first study (Lappe 2007, N= 1,169, median serum level = 30 ng/ml) and used the pooled cohort to investigate cancer incidence over time (median = 3.9 years). Combining cohorts gave us a wider range of serum levels, more data, and thus improved statistical power. We looked at all invasive cancers combined, excluding skin cancer.
This analysis found a 71% lower risk of all type cancer with vitamin D levels greater than 40 ng/ml as compared to levels less than 20 ng/ml.
What would you do?
If it takes a year for vitamin D to have an effect on your system, when should you start ensuring that your vitamin D level is 50 ng/ml or higher? If you are a parent, when would you start with your child? At 10 years old? As a teen? When they leave the house? Or as a baby - to ensure the healthiest life possible?
|
What is the New York Times Writing About?
On April 10th, 2017 the
New York Times picked up the press release from the
Journal of the American Medical Association,
JAMA, and printed a story entitled, "
Why are so many people popping vitamin D?" by Gina Kolata.
Their summary for the article was, "There is no epidemic of vitamin D deficiency, experts say, yet pointless testing and treatment are rampant."
This article was very poorly written and researched. Where's the evidence that says there is 'no epidemic'?
GrassrootsHealth, along with 48 other vitamin D researchers, would disagree.
Further, the article says "...vitamin D has become popular even among people with no particular medical complaints or disease risks." Where does prevention come in? They indicate that unless you HAVE osteoporosis or some medical condition you don't need testing.
There is no indication or appreciation of the variation in serum level by an individual and that for a given intake, the serum level response can vary 6 fold.
The article starts by complaining that one in five people in Maine request a vitamin D blood test during their routine check ups. GrassrootsHealth believes that number should be five out of five. So yes - they have the right to complain! What is the cost for a blood test and supplements for a year? Probably $200 for the year. What is the cost of cancer? Of diabetes? Of pain? How much money do you put on quality of life?
Next, the article complains that Medicare is spending too much money on vitamin D testing. Again, this population is at risk of osteoporosis, falls, and many diseases. What is the cost of testing and supplementing vs. one hospitalization for a fall?
My favorite line is, "some are taking supplemental doses so high they can be dangerous, causing poor appetite, nausea and vomiting." There is no reference. There is no source. This is just a statement. First of all, to get to this level you need to have a vitamin D level greater than 200 ng/ml.
Published literature shows no toxicity under 200 ng/ml and 30,000 IU/day. While this is true that it can cause poor appetite, nausea and vomiting - this is generally caused by extreme dosing (i.e. 500,000 IU/day) and these doses are usually due to error. Finally, reports of overdosing show that, when the subject stops taking the extreme dose of vitamin D the body regulates back to normal.
Dr. JoAnne E. Manson is quoted, a researcher at Brigham and Women's Hospital in Boston. She is currently the lead investigator for a study called
VITAL, which is a multi-year, randomized controlled population study testing how effective daily vitamin D and Omega 3 supplements are to health. The treatment group in this trial receives 2000 IU vitamin D a day. This is three times the current RDA for a normal adult. Why would she choose that if she didn't think the RDA was too low? Is she testing vitamin D levels in her VITAL study so she can track outcomes to the biological measure, the serum levels?
Kolata cites Dr. Michael F. Holick as a renowned vitamin D researcher, but did not use any of his arguments - just stating that he believes that there is an association between low vitamin D and disease. In addition, they have him quote the current RDA when Dr. Holick does not recommend the RDA dosage. His web site,
drholick.com, recommends 1500-2000 IU/day for most adults.
The article then focuses on two recent studies that show no correlation between vitamin D and lower risk. Really???
The proof is in the details... always.
The first study cited was by Robert Scragg et al. and published in JAMA on April 5, 2017. It showed that the treatment arm and placebo arm had the same incidence of cardiovascular disease. But... as you delve deeper you find that the treatment arm used monthly, or bolus, dosing. They received 100,000 IU vitamin D - once a month. This type of dosing has been shown to be
ineffective to help immune function, bolus dosing may only be good for bone health. So this outcome is not at all surprising.
The second study was Dr. Lappe's recent cancer study, which did find a 35% reduction in the treatment group, with a significant P-value, after excluding the data on the first year of the trial. I would say this is significant. We have written a
detailed description here if you want to learn more about this paper.
The rest of the article documents the progression of vitamin D papers, to new recommendations and increased testing. The National Health and Human Services division does health surveys and they didn't start measuring vitamin D levels until 1988, but I wish they had numbers from earlier on, especially on children. If there were data showing that children in the 1960's had vitamin D levels of 40-50 ng/ml, as some surmise, combined with the rates of childhood diseases today - we wouldn't be having this discussion.
The national average 25(OH)D level, according to NHANES 2009-2010, is 22 ng/ml.
The article ends on a note comparing yearly vitamin D screening to yearly cholesterol screening. The cost for cholesterol screening is approximately $140 (to find total, HDL, LDL, triglicerydes) at LabCorp or Quest. The costs of 25(OH)D testing is about $70 through LabCorp or Quest. But yet cholesterol testing is accepted. Why? Because the science for the correlation of cholesterol and heart disease is over 50 years old, for vitamin D it is only about 15 years old. So, do we have to wait until the industry catches up?
|
|
| |
|
|
|
|
|
Buy 2 get 1 Free
in April with coupon code
B2G1FREE
|
|
|
Free Shipping
in the US in April with coupon code
GRHealth
|
|
|
|
10% off
in April with coupon code GRHApr10
|
|
|
Why are so many people popping vitamin D?
Gina Kolata
New York Times
April 10, 2017
Rebuttals:
GrassrootsHealth News
A review of randomized controlled trials with vitamin D and cancer
April 7, 2017
GrassrootsHealth Release
Press Release
To give the press reasons and explanation for why the last trial was "not significant"
|
|
|
Vitamin D status in a rural postmenopausal female population
Joan M. Lappe, et al.
The Journal of the American College of Nutrition
October 2006
Vitamin D and calcium supplementation reduces cancer risk: results of a randomized trial
Joan M. Lappe, et al.
American Journal Clinical Nutrition
June 2007
Serum 25-Hydroxyvitamin D Concentrations ≥40 ng/ml are Associated with >65% Lower Cancer Risk: Pooled Analysis of Randomized Trial and Prospective Cohort Study
Sharon L. McDonnell, et al.
GrassrootsHealth
PLOS One
April 2016
Effect of Vitamin D and Calcium Supplementation on Cancer Incidence in Older Women - A Randomized Clinical Trial
Joan Lappe, et al.
Journal of American Medical Association
March 28, 2017
|
|
|
|
Click here to receive weekly news from GrassrootsHealth.
|
| Share this Newsletter |
Share this newsletter on Facebook!
Click on the top left social share buttons
to share this entire newsletter.
|
|
|
