By Dr. Mercola
Last November, researchers at the Kaiser Permanente Center for Health Research1 declared that vitamin supplements are probably useless when it comes to preventing heart disease and/or cancer.
Their seriously flawed analysis (which, sadly, is being used by the US Preventive Services Task Force to update its recommendations on supplement use) was widely reported by the media.2
Now, the attack against vitamin supplements has heated up yet again—this time they're trying to quell the idea that vitamin D, specifically, has any useful purpose for the average person.
Numerous media sources3, 4 have trumpeted the findings of a recent meta-analysis,5 which claims that vitamin D supplements are not only useless against heart disease, stroke and cancer, but may do more harm than good, and that further investigation into vitamin D would likely be "pointless"! According to the authors of the study:
"Available evidence does not lend support to vitamin D supplementation and it is very unlikely that the results of a future6 single randomized clinical trial will materially alter the results from current meta-analyses."
What's more, they also found that people taking vitamin D supplements had an increased risk for hip fracture, which prompted Professor Karl Michaëlsson, a researcher at Uppsala University in Sweden, to publish a call for stricter labeling on vitamin D supplements. In his editorial,7 which accompanied the featured analysis, he writes:
"Without stringent indications -- i.e. supplementing those without true vitamin D insufficiency -- there is a legitimate fear that vitamin D supplementation might actually cause net harm."
It should be noted that the dose given to the women in the study with increased fracture rates was 500,000 IU, all in one dose. This is an intake the body cannot absorb and process properly and the toxicity of the dose itself was not a surprise to the vitamin D researchers. The increased fractures were seen shortly after the huge dose but the rate declined in later months.
Research Shows Vitamin D Sufficiency Is Critical for Good Health
Meanwhile, a robust and rapidly growing body of research clearly shows that vitamin D is absolutely critical for good health and disease prevention, in part due to the fact that it influences about 10 percent of all your genes.
Just one example of an important gene that vitamin D upregulates is your ability to fight infections and chronic inflammation. It also produces over 200 anti-microbial peptides, the most important of which is cathelicidin, a naturally occurring broad-spectrum antibiotic.
Since the early 2000s, scientific investigations into the effects of vitamin D have ballooned. By the end of 2012, there were nearly 34,000 published studies on the effects of vitamin D, and there are well over 800 references in the medical literature showing vitamin D's effectiveness against cancer alone. According to Carole Baggerly, founder of GrassrootsHealth, as much as 90 percent of ordinary breast cancer may in fact be related to vitamin D deficiency.
Granted, the featured review is rebuking vitamin D supplements only. They're not trying to claim that vitamin D deficiency doesn't have any repercussions for your health. On the contrary, it supports the notion that sun exposure is your best source of vitamin D, as your skin naturally creates it in response to UV radiation.
However, many people, especially those living in northern latitudes, are simply unable to get the necessary sun exposure needed to maintain clinically relevant vitamin D levels of 50-70 ng/ml year-round.
Vitamin D Synthesis Is Unlikely During Winter Months...
The US map below shows the likelihood of vitamin D synthesis during February. My Vitamin D Resource page also contains maps showing vitamin D synthesis in various US states for the rest of the year. As you'll see, even if you live in the southernmost states, optimal vitamin D synthesis will not occur until June!
I firmly believe that UVB exposure is a far healthier way to optimize your vitamin D levels, but if you can't use the sun or a safe tanning bed then it is best to use an oral supplement, but please recognize that it's an inferior choice.
Vitamin D supplements are also among the least expensive, and the health impact of deficiency is so broad and detrimental that it simply makes little sense to scare people away from vitamin D supplements—unless you've got some ulterior reason for doing so.
As I will discuss below, you DO benefit from taking other nutrient ratios into account when you use a vitamin D supplement though, which makes supplementation a bit more complex, compared to raising your levels through sun exposure.
Vitamin D Supplements Under Fire
The analysis, published in the journal Lancet Diabetes & Endocrinology,8 looked at 40 previously published randomized controlled trials of vitamin D supplements, with or without calcium, concluding that vitamin D supplements do not reduce the risk of heart attacks, strokes, cancers, or bone fractures in the general population by more than 15 percent.
What's more, the researchers claim the effects of vitamin D supplementation are below a "futility threshold," (not a surprise when the average dose was 400-800 IU/day, already demonstrated to be ineffective) effectively rendering further investigations unnecessary. Attacks have been repeatedly made against nutritional supplements and the value of nutrition for disease prevention in general, but we may have reached a new low. WebProNews.com even went so far as to say that:
"Further studies show unborn babies do not get any benefits from the vitamin when taken by pregnant women."
The studies were not referenced so it is impossible to understand what led them to this mistake, but I'm firmly convinced that this is incorrect and may lead many mothers completely astray. Your baby will be born with approximately 60-70 percent of whatever your (the mother's) vitamin D level is.
According to Dr. David Ayoub, who has testified in hundreds of cases of infantile rickets misdiagnosed as child abuse, mothers who are deficient in vitamin D, with levels around 18-19 ng/ml, have a significantly greater risk of having children with infantile rickets.
Make no mistake about it: optimizing your vitamin D levels during pregnancy is absolutely CRITICAL for your baby's development. Granted, your best bet is to make sure you're getting plenty of sun exposure. Unfortunately, women in general are heavily indoctrinated to fear sun exposure, which has led to a virtual epidemic of vitamin D deficiency.
Another study9 by the same New Zealand research team, published in October of last year, concluded that people with vitamin D deficiency and evidence of bone loss are the only ones that should be taking vitamin D. This too flies in the face of mounting research from premier vitamin D research organizations such as GrassrootsHealth.10
The Vitamin D Controversy Heats Up
In the featured video at the top of this article, Carole Baggerly interviews Dr. Cedric Garland of UCSD Moores Cancer Center about this latest meta-review.11 Another prominent vitamin D expert and researcher, Dr. Michael F. Holick, M.D., PhD., author of The Vitamin D Solution, has also dismissed the analysis, calling it flawed and "silly." (Incidentally, Dr. Holick is the person responsible for identifying the major circulating form of vitamin D—25-hydroxyvitamin D3—which is the form of vitamin D doctors typically measure now to assess vitamin D status.) According to Dr. Garland:
"This meta-analysis is nothing new and is already obsolete, since it is mainly based on old papers that used too little vitamin D to expect any effect. A New Zealand study saying we should only supplement people with vitamin D deficiency and evidence of bone loss is equally wrong. Virtually everyone in New Zealand, and most adults in the US, are vitamin D deficient by modern criteria, being below 32 ng/ml.
The reality is that we now know that they are deficient with regard to extraskeletal effects of 25(OH)D if their serum level is below 40 ng/ml. These papers should be disregarded as obsolete work. We are moving into a new era of using vitamin D3 in doses no less that 4,000 IU/day for people aged 9 years and older... Studies using less than 4,000 IU/day are on the verge of obsolescence."
Why the Latest Vitamin D Analysis Is Meritless
Drs. Holick and Garland both point out the futility of looking at studies using subclinical doses of vitamin D—they're not going to show results, and for very obvious reasons. Robust evidence shows that 400 IUs of vitamin D per day is nowhere near enough. That's only about one-tenth of the effective dose! The authors of the analysis also did not include any epidemiological research, and completely ignored the most truly relevant randomized controlled trial on vitamin D and cancer.
Research published in 2007 by Lappe et.al.12 showed that after four years of follow up, there was a 77% cancer risk reduction in women who received 1,100 IUs of vitamin D and 1,450 mg calcium per day, and, achieved a serum level of approximately 40 ng/ml. The serum level is the marker we are aiming for. The serum level of those who received either a placebo or calcium by itself was approximately 30 ng/ml. If a 77 percent risk reduction is not relevant, I don't know what is.
"The Lappe et al. study and the many supportive epidemiological studies that preceded and followed it should prove to even the most ill-informed skeptic that vitamin D prevents most cancer," Dr. Garland says. "It is incredible that the authors of this review virtually disregarded all of the relevant epidemiology this randomized controlled clinical trial."
Further, according to Dr. Leo Baggerly, Sr. Research Scientist at GrassrootsHealth, "the authors of this review 'reanalyzed' the results of the Lappe study in a completely invalid manner and included their 'corrected' results in their summary, while virtually disregarding the actual study results."
The analysis' conclusion on vitamin D is in stark contrast to an ever growing number of studies showing that vitamin D (with or without calcium) has tremendous protective effect against cancer specifically. For example, another 2007 study published in the American Journal of Preventive Medicine13 concluded that a serum 25(OH)D level of more than 33 ng/mL was associated with a 50 percent lower risk of colorectal cancer.
A recent Cochrane meta-review14 published in January of this year also concluded that even low dose vitamin D supplementation appears to reduce cancer mortality by almost 15 percent. Theories linking vitamin D deficiency to cancer have been tested and confirmed in more than 200 epidemiological studies, and understanding of its physiological basis stems from more than 2,500 laboratory studies. So, in a nutshell, there are two significant issues that render the featured analysis without merit:
- The studies included used vitamin D supplements in doses that are not clinically relevant. Adults need anywhere from 10-20 times the amount used in the studies to protect against heart disease and cancer—4,000 to 8,000 IUs a day, compared to the 400-800 IUs used in the studies
- The studies have mistakenly been shooting for vitamin D levels in the 20-30 ng/ml range, which vitamin D experts today believe is HALF of what you really need for disease prevention. Ideally, you'll want a vitamin D level above 50 ng/ml, but a bare minimum of 40 ng/ml is recommended15
As noted Dr. John Cannell of the Vitamin D Council, the authors excluded no less than one dozen randomized controlled trials, the majority of which were positive.
"The authors argued that more trials of vitamin D are a waste of money and resources and will be negative," Dr. Cannell writes. "Luckily researchers at Harvard do not agree, as we all wait for their VITAL study results expected around 2017. It is a study of 20,000 healthy Americans, half of which will take an extra 2,000 IU/day compared to a group of 10,000 subjects getting a vitamin D placebo.
The study will measure vitamin D blood levels in all subjects, so we will know if any of the placebo group started taking vitamin D. It will give us specific results for those subjects who obtained blood levels of > 40 ng/ml. The VITAL study will measure dozens of clinical endpoints with cancer and cardiovascular disease being the primary end points. I will be shocked if 2,000 IU/day has no effect on any clinical endpoint."
The study that we are supporting, the D*action study run by GrassrootsHealth, is the only prospective study that actually has 1000's of subjects in the 40-60 ng/ml range. They are tracking many health outcomes such as breast cancer, pain, diabetes, as well as reporting on the dose response information. Initial publications have already been made with kidney stones (no increased risk) and a dose response relationship showing that to get approximately 97% of the population to 40 ng/ml, it will take 10,000 IU/day to achieve that. New papers are to be released soon on a very significant prevention effect with diabetes and pain levels. There is no need to wait to track your own health outcomes and achieve the benefits of the appropriate serum levels.
Are You Vitamin D Deficient?
Some news sources, such as the Star Tribune,16 have noted that high-risk groups such as babies, pregnant women, and the elderly are still advised to take vitamin D supplements. The thing is, a majority of people, regardless of age, sex, or nationality, are in fact low or deficient in vitamin D, and stand to benefit from raising their levels into the clinically significant levels, which is higher than the recommended "normal." (For more information, see the next section below.) Before the year 2000, very few doctors ever considered the possibility that you might be vitamin D deficient. But as the technology to measure vitamin D became inexpensive and widely available, more and more studies were done, and it became increasingly clear that vitamin D deficiency was absolutely rampant. For example:
- The Centers for Disease Control and Prevention (CDC) reported that 32 percent of children and adults throughout the US were vitamin D deficient
- The National Health and Nutrition Examination Survey found that 50 percent of children aged one to five years old, and 70 percent of children between the ages of six and 11, are deficient or insufficient in vitamin D
- Researchers such as Dr. Holick estimate that 50 percent of the general population is at risk of vitamin D deficiency and insufficiency
Make Sure Your Levels Are in a Clinically Relevant Range
When it comes to vitamin D, you don't want to be in the "average" or "normal" range, you want to be in the "optimal" range. The reason for this is that as the years have gone by, researchers have progressively moved that range upward. At present, based on the evaluation of healthy populations that get plenty of natural sun exposure, the optimal range for general health appears to be somewhere between 50 and 70 ng/ml. As previously explained by Dr. Holick:
"Both the IOM (Institute of Medicine) and the Endocrine Society acknowledge in treatment guidelines that 10,000 IU/day is considered the No Observed Adverse Effect Level (NOAEL). Most treatments to get serum levels in the 40-60 ng/ml range are likely to be below that level.
GrassrootsHealth has also been looking at this issue and also recommends 40 to 60 nanograms per milliliter as the ideal level (see above)... A study was done in Maasai warriors who are outside every day. That really gives us an insight where we should all be with our blood levels of 25-hydroxyvitamin D. They were found to be around 50 nanograms per milliliter."
Now Is a Great Time to Test Your Vitamin D Levels
The month of February is typically when you have the least amount of sun exposure, so right now is an ideal time to test your vitamin D levels to get an idea of what your levels are at their lowest. If you're low, take proactive measures to raise your levels, and then retest in mid-summer.
The D*Action Project by GrassrootsHealth is a very cost effective solution. To participate, simply purchase the D*Action Measurement Kit and follow the registration instructions included. (Please note that 100 percent of the proceeds from the kits go to fund the research project. I do not charge a single dime as a distributor of the test kits.)
As a participant, you agree to test your vitamin D levels twice a year during a five-year study, and share your health status to demonstrate the public health impact of this nutrient. There is a $65 fee every six months for your sponsorship of this research project, which includes a test kit to be used at home, and electronic reports on your ongoing progress. You will get a follow up email every six months reminding you "it's time for your next test and health survey."
As for HOW to optimize your vitamin D levels, I firmly believe that appropriate sun exposure is the best way. In fact, I personally have not taken a vitamin D supplement for three or four years, yet my levels are in the 70 ng/ml range. There's a handy smartphone app called DMinder (dminder.info) that will tell you how much UV radiation you're getting and how many IUs of vitamin D you're making based on your local weather conditions (reported from the weather service) and other individual parameters such as your skin tone and age. It will also tell you when to get out of the sun, to protect yourself from sunburn.
If you can't get enough sunshine, then a safe tanning bed would be your next best option. Most tanning equipment use magnetic ballasts to generate light. These magnetic ballasts are well-known sources of EMF fields that can contribute to cancer. If you hear a loud buzzing noise while in a tanning bed, it has a magnetic ballast system. I strongly recommend you avoid these types of beds and restrict your use of tanning beds to those that use electronic ballasts.
If your circumstances don't allow you to access the sun or a safe tanning bed, then you really only have one option if you want to raise your vitamin D, and that is to take a vitamin D supplement. GrassrootsHealth has a helpful chart showing the average adult dose required to reach healthy vitamin D levels based upon your measured starting point. Many experts agree that 35 IUs of vitamin D per pound of body weight could be used as an estimate for your ideal dose.
If You Opt for Oral Vitamin D, Remember Vitamin K2
Last but not least, if you do opt for a vitamin D supplement, you also need to take vitamin K2. The biological role of vitamin K2 is to help move calcium into the proper areas in your body, such as your bones and teeth. It also helps remove calcium from areas where it shouldn't be, such as in your arteries and soft tissues.
Vitamin K2 deficiency is actually what produces the consequences similar to vitamin D toxicity, which includes inappropriate calcification that can lead to hardening of your arteries. The reason for this is because when you take vitamin D, your body creates more vitamin K2-dependent proteins that move calcium around in your body. Without vitamin K2, those proteins remain inactivated, so the benefits of those proteins remain unrealized. So remember, if you take supplemental vitamin D, you're creating an increased demand for K2. Together, these two nutrients help strengthen your bones and improve your heart health.