By Dr. Mercola
Researchers such as Dr. Robert Heaney, who I previously interviewed in the above video, have now realized that vitamin D is involved in the biochemical “machinery” of all cells and tissues in your body, which is why it has such a potent impact on health and disease.
When you don’t have enough, your entire body will end up struggling to function properly, because all cells need the active form of vitamin D to open up the genome and access the information retained within its genetic plans.
When you’re deficient in vitamin D, your health can deteriorate in any number of ways from this lack of access to the cells’ genetic blueprint.
Researchers have previously pointed out that increasing levels of vitamin D3 among the general population could prevent chronic diseases that claim nearly one million lives throughout the world each year.
Chances are this number would reach even higher if more recent research were to be taken into account. Either way, compelling evidence suggests that optimizing your vitamin D can reduce your risk of death from any cause,1 making it a foundational component of optimal health.
Childhood Vitamin D Deficiency Can Be Costly in Terms of Health
For years, it’s been known that children born to vitamin D-deficient mothers are at increased risk for type 1 diabetes. Vitamin D deficiency in childhood is also associated with more severe asthma and allergies.
Recent research also suggests that having low vitamin D levels in childhood may raise your risk of hardening of the arteries in middle-age. The study,2 published in the Journal of Clinical Endocrinology & Metabolism, involved nearly 2,150 people who were enrolled in 1980 at the age of 3-18. As reported by the New York Times:3
“All underwent periodic physical exams, including measures of serum vitamin D levels, blood pressure, lipid levels, diet, smoking, and physical activity and were examined up to age 45.
Doctors used ultrasound to examine arteries, including the carotid artery in the neck; thickening of the arteries is considered a marker of higher cardiovascular risk.
A vitamin D level of between 30 to 50 is generally considered adequate. Children in the lowest one-quarter for vitamin D levels, about 15 nanograms per milliliter, were nearly twice as likely to have thickening of the carotid artery as those in the other three quarters.”
According to lead author, Dr. Markus Juonala, a professor of internal medicine at the University of Turku in Finland, the findings suggest that vitamin D plays a role in long-term arterial health.
Here, they did not find that low vitamin D in childhood resulted in any specific heart conditions or stroke later in life, but other studies have indeed noted a strong connection between low vitamin D in adults and such health problems.
Low Vitamin D May Predict More Severe Stroke
According to veteran vitamin D researcher Dr. Michael Holick, research has shown that vitamin D deficiency can increase your risk of heart attack by 50 percent. Moreover, if you have a heart attack and you're vitamin D deficient, your risk of dying from that heart attack is upwards of 100 percent!
Similarly, findings presented at this year’s annual American Stroke Association's International Stroke Conference suggest that people who have low vitamin D status are far more likely to suffer more severe strokes.
They also have poorer outcomes after suffering a stroke compared to those with more adequate vitamin D levels. As reported by the American Heart Association:4
“[Stroke] patients who had low vitamin D levels –defined as less than 30 nanograms per milliliter (ng/mL) – had about two-times larger areas of dead tissue resulting from obstruction of the blood supply compared to patients with normal vitamin D levels...
For each 10 ng/mL reduction in vitamin D level, the chance for healthy recovery in the three months following stroke decreased by almost half, regardless of the patient's age or initial stroke severity.”
Virtually All Cancer Patients Have Low Vitamin D Levels
Low vitamin D is also strongly associated with an increased risk for well over a dozen different cancers, including breast and colon cancer. Theories linking vitamin D deficiency to cancer have been tested and confirmed in hundreds of epidemiological studies, and understanding of its physiological basis stems from more than 2,500 laboratory studies.
Its anticancer effects include the promotion of apoptosis (cancer cell death), and the inhibition of angiogenesis (the growth of blood vessels that feed a tumor), and the level of protection afforded by vitamin D can indeed be significant. For example:
- One recent meta-analysis5 found that having a high serum level of 25-hydroxyvitamin D was associated with a 25 percent reduction in relative risk of bladder cancer
- A 2007 study published in the American Journal of Preventive Medicine6 concluded that a vitamin D level of more than 33 ng/mL was associated with a 50 percent lower risk of colorectal cancer
- Researchers7,8 Joan Lappe and Robert Heaney found that menopausal women given enough vitamin D to raise their serum levels to 40 ng/ml experienced a 77 percent reduction in the incidence of all cancers after just four years’ of supplementation
- According to Carole Baggerly, founder of GrassrootsHealth,9 the evidence suggests as much as 90 percent of ordinary breast cancer may be related to vitamin D deficiency
Link Between Vitamin D Levels and Colorectal Cancer Strengthened
Not only does vitamin D protect against tumor proliferation in the first place, it also affects treatment outcome and recovery. The connection between vitamin D status and cancer survival was most recently demonstrated in research presented at the annual Gastrointestinal Cancers Symposium.
Patients diagnosed with metastatic colorectal cancer who had higher levels of vitamin D had a far greater progression-free survival rate than those who were deficient. As reported by Clinical Oncology:10
“The study’s lead investigator, Kimmie Ng, MD, MPH... said the research adds to the existing evidence that vitamin D levels have an effect on cancer. Vitamin D is known to inhibit cell proliferation and angiogenesis, induce cell differentiation and apoptosis and have anti-inflammatory effects.
“Many of these processes are dysregulated in cancer, which led to the hypothesis that perhaps vitamin D had anticancer activity,” said Dr. Ng. Laboratory data support this hypothesis, with experiments demonstrating that administering vitamin D to mice with intestinal cancer reduces tumor burden.”
Nearly 1,045 patients with metastatic colorectal cancer were included in the study, and the median vitamin D level among them was just over 17 ng/ml. Few of them reported taking any kind of vitamin D supplement. Typically, anything below 20 ng/ml is considered a serious deficiency state that increases your chances of any number of health problems, including cancer. Many studies show that having adequate vitamin D is critical in order to optimize treatment outcome. Here, Dr. Ng noted that: “Patients who had levels in the highest quintile had a median survival of 32.6 months compared with 24.5 months for patients with levels in the lowest quintile.”
The Many Health Risks of Low Vitamin D
Vitamin D is one of the most well-researched nutrients out there, and the evidence overwhelmingly points to the fact that it is critical for optimal health and disease prevention. 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.
I’m thoroughly convinced that optimizing your vitamin D stores can go a long way toward preventing disease and living a longer, healthier life, as the known health benefits of vitamin D now number in the hundreds, if not thousands. Besides cancer and cardiovascular disease, other benefits of vitamin D include protection against:
Autoimmune diseases. Vitamin D is a potent immune modulator, making it very important for the prevention of autoimmune diseases, like multiple sclerosis11 (MS) and inflammatory bowel disease.
Lung disease. In those who are deficient, vitamin D supplementation may reduce flare-ups of chronic obstructive pulmonary disease (COPD) symptoms by more than 40 percent.12 Other research13 suggests vitamin D may protect against some of the adverse effects of smoking as well.
Infections, including influenza. Vitamin D also fights infections, including colds and the flu, as it regulates the expression of genes that influence your immune system to attack and destroy bacteria and viruses. I believe it's far more prudent, safer, less expensive, and most importantly, far more effective to optimize your vitamin D levels than to get vaccinated against the flu.
DNA repair and metabolic processes. One of Dr. Michael Holick’s studies showed that healthy volunteers taking 2,000 IUs of vitamin D per day for a few months upregulated 291 different genes that control up to 80 different metabolic processes. This included improving DNA repair; having a beneficial effect on autoxidation (oxidation that occurs in the presence of oxygen and /or UV radiation, which has implications for aging and cancer, for example); boosting the immune system; and many other biological processes.
Brain health,(depression,14,15 dementia, and Alzheimer’s disease). Vitamin D receptors appear in a wide variety of brain tissue, and activated vitamin D receptors increase nerve growth in your brain. Vitamin D is therefore important for optimal brain function, mental health, and for the prevention of degenerative brain disorders, including Alzheimer’s disease. According to one recent study,16,17 seniors with low vitamin D levels may double their risk of dementia and Alzheimer’s disease.
Another study18,19,20 found that people with the highest average intakes of vitamin D had a 77 percent decreased risk for Alzheimer's. Researchers believe that optimal vitamin D levels may enhance the amount of important chemicals in your brain and protect brain cells by increasing the effectiveness of the glial cells in nursing damaged neurons back to health. Vitamin D may also exert some of its beneficial effects on your brain through its anti-inflammatory and immune-boosting properties.
How Much Vitamin Do You Need?
Dr. Robert Heaney is a professor and a well-respected vitamin D researcher, having studied this nutrient for more than 50 years. In the interview above, he shares many of his insights into this question. As a general guideline, an ideal, and what needs to be reclassified as normal, vitamin D level is in the range of 40-60 ng/ml. According to Dr. Heaney, research has shown that 40-60 ng/ml is the level a nursing mother needs in order to ensure her milk will contain the vitamin D her nursing infant needs. The 40-60 ng/ml range is also the same range needed for thyroid health, and it’s the range found in tribal populations living on the equatorial plains of East Africa.
Dr. Heaney has pointed out new research showing that oral sources of vitamin D are much higher than previously thought, and this provides compelling justification for the use of oral supplementation. But virtually every expert I have asked does believe that vitamin D produced from the UVB exposure provides additional therapeutic benefits. But for most people, winter precludes anything other than to increase their oral vitamin D supplementation.
That said, sensible sun exposure appears to be the best way to optimize your vitamin D level. Dr. Heaney stresses that you need to get approximately 5,000 to 6,000 IUs of vitamin D per day from all sources – sun, supplements, and food – in order to reach and maintain a blood level of 40-60 ng/ml.
Keep in mind that the specific dosage is a very loose guideline, because people vary widely in their ability to respond to vitamin D. GrassrootsHealth—which Dr. Heaney is Research Director of—also has a helpful chart showing the average adult dose required to reach healthy vitamin D levels based upon your measured starting point. Ideally, make sure to monitor your levels at regular intervals, and take whatever amount of vitamin D3 you need to maintain a clinically relevant level year-round. Do remember to take vitamin D3—not synthetic D2—along with vitamin K2 and magnesium. To learn more about the reason for this recommendation, please see my previous article, “Magnesium—The Missing Link to Better Health.”