It is estimated that up to 85 percent of people have insufficient levels of vitamin D and are unaware of their deficient state. While conventional media and medicine promote sun avoidance, doing so can actually put your health in grave danger and cause vitamin D deficiency.
The Role of Vitamin D in Disease Prevention
A growing body of evidence shows that vitamin D plays a crucial role in disease prevention and maintaining optimal health. There are about 30,000 genes in your body, and vitamin D affects nearly 3,000 of them, as well as vitamin D receptors located throughout your body.
According to one large-scale study, optimal vitamin D levels can slash your risk of cancer by as much as 60 percent. Keeping your levels optimized can help prevent at least 16 different types of cancer, including pancreatic, lung, ovarian, prostate, and skin cancers. Moreover, vitamin D can build your defenses against cancer by:
- Enhancing the self-destruction of mutated cells (which can replicate and cause cancer)
- Slowing down the production and spread of cancer cells
- Helping in the differentiation of cells (cancer cells are not differentiated)
- Preventing the formation of new blood vessels from pre-existing ones (this can help stop the progress of benign tumors into cancerous ones)
Vitamin D can also help reduce the risk of other conditions as well, including type 2 diabetes, chronic inflammation, age-related macular degeneration (the leading cause of blindness), and Alzheimer’s disease.
Vitamin D also exhibits its infection-fighting abilities in the treatment of tuberculosis, pneumonia, colds, and flu. It can also improve seizure control in epileptics.
While scientists refer to vitamin D as a vitamin, it is actually a steroid hormone obtained from sun exposure, food sources, and supplementation. Common types of vitamin D are vitamin D2 and D3. Compared to D2, vitamin D3 is 87 percent more effective, and is the preferred form for addressing insufficient levels of vitamin D.
The Vitamin D Epidemic in the United States
Today, many Americans are found to be in a serious deficiency state. Over 95 percent of senior citizens in the US may possibly be deficient, along with 85 percent of Americans. The late winter average vitamin D level was found to be about 15 to 18 ng/ml, which is far below optimal levels.
Cases of vitamin D deficiency are also seen more frequently in individuals (of all ages) that have increased skin pigmentation, including those whose ancestors are from Africa, the Middle East, or South Asia.
This deficiency problem also applies to people who often use sun protection, or those who spend more time indoors than outdoors. Regardless of skin pigmentation, deficiency can be even worse if they live in northern latitudes, as there is very little sun exposure (I'll discuss this in a bit).
The Vitamin D and Vitamin K2 Connection
Dr. Mercola Interviews Dr. Kate Rheaume-Bleue
Another critical point to remember is you shouldn't take any vitamin D supplement without taking vitamin K2. Vitamin K2 deficiency is connected to vitamin D toxicity symptoms, which includes excessive calcification that can contribute to the hardening of your arteries.
One of the functions of vitamin K2 is to direct calcium to areas in your body where it is needed, such as your bones and teeth. It also functions to keep calcium away from areas where it shouldn’t be, including your soft tissues and arteries.
According to Dr. Kate Rheaume-Bleue, author of Vitamin K2 and the Calcium Paradox: How a Little Known Vitamin Could Save Your Life:
"When you take vitamin D, your body creates more of these vitamin K2-dependent proteins, the proteins that will move the calcium around. They have a lot of potential health benefits. But until the K2 comes in to activate those proteins, those benefits aren't realized. So, really, if you're taking vitamin D, you're creating an increased demand for K2. And vitamin D and K2 work together to strengthen your bones and improve your heart health.
...For so long, we've been told to take calcium for osteoporosis... and vitamin D, which we know is helpful. But then, more studies are coming out showing that increased calcium intake is causing more heart attacks and strokes. That created a lot of confusion around whether calcium is safe or not. But that's the wrong question to be asking, because we'll never properly understand the health benefits of calcium or vitamin D, unless we take into consideration K2. That's what keeps the calcium in its right place"
The optimal ratios between vitamin D and K2 have yet to be determined. However, Dr. Rheaume-Bleue recommends that for every 1,000 IUs of vitamin D, you can benefit from about 100 to 200 micrograms of vitamin K2.
Healthy Sun Exposure Is Your Best Source of Vitamin D
Dr. Mercola on Healthy Sun Exposure
I strongly recommend ample sunlight exposure as your main source of vitamin D, as the sun provides beneficial UVB wavelengths that are needed to optimize your levels.
Although most dermatologists will tell you to avoid the sun to prevent diseases like cancer, exposure can actually aid in skin cancer prevention – and there are studies confirming this. Melanoma occurrence is found to decrease with greater exposure to direct sunlight. According to a study published in the European Journal of Cancer, melanoma was found to be more common in workers who spent time indoors, and in body parts that are not exposed to the sun.
The sun emits two types of wavelengths at different periods in a day: UVA rays and UVB rays. Your body requires UVB for vitamin D production. UVA rays, on the other hand, have longer wavelengths and can penetrate the ozone layer, as well as clouds and pollution. Frequent exposure to this type of wavelength increases your risk of skin cancer and photoaging.
Occasional exposure of your hands and face to the sun does not constitute appropriate sunlight exposure. To optimize your levels, large portions of your skin needs to be exposed to the sun. However, over exposure to the sun can result in sunburn, which will increase your risk for skin cancer and premature skin aging.
Once you get the proper amount of sunlight, your body will stop producing vitamin D because of its self-regulating mechanism. Here are other important factors in safe sunlight exposure:
- Time – The best time to expose yourself to the sun is as near to solar noon as possible (during Daylight Savings Time, solar noon is typically around 1 pm). UVB rays, unlike UVA rays that are present all throughout the day, are very low in the morning and evening, and are abundant during midday – around 10:00 am to 2:00 pm. Expose yourself to direct sunlight between these times for a short period, and you will have produced the most vitamin D3.
- Skin pigmentation – Fair-skinned people can potentially max out their vitamin D production in just 10 to 20 minutes, or when their skin has turned the lightest shade of pink. However, if you have darker skin, you likely need to remain in the sun longer.
- Sensitive body parts – The skin located around your eyes is thinner compared to other areas on your body. Since it has a small surface area, it will not do much to contribute to vitamin D production. You need to protect this part of your face, as it is very prone to photoaging and premature wrinkling. I recommend using a safe sunblock or wearing a cap that will keep your eyes in the shade.
If you get sunburned, aloe vera is one of the best remedies to help repair your skin. This plant is loaded with powerful glyconutrients that will induce healing. I suggest deriving the gel from a fresh plant.
- Using soap – When UVB rays strike the surface of your skin, your skin will then convert a cholesterol derivative, which will turn into vitamin D3. However, the produced vitamin D3 does not immediately enter your bloodstream. It may take up to 48 hours before the vitamin D3 penetrates into your bloodstream.
When you shower immediately after sun exposure, you risk washing away the vitamin D3 formed by your skin and potentially reduce the benefits of sun exposure.
While those living in tropical regions have an abundance of sunshine, there are individuals who hardly have exposure, especially in most of the continental US. It doesn’t make much sense to expose your skin to the sun when the temperature is lower than 50 degrees F, which has a scarcity of UVB rays. This occurs a lot in most regions in the US, especially those who experience four seasons.
The charts below display the likelihood of vitamin D synthesis across the U.S. by month.
In those times of the year when UVB rays are very minimal, it may be wise to use a safe tanning bed that utilizes UVB rays, or to take a high-quality vitamin D3 supplement.
Using a Safe Tanning Bed
Dr. Mercola on Safe Tanning Beds
You’ve probably heard about warnings that may dissuade you from using a tanning bed. But not all tanning beds are created equal. To make sure you are getting safe exposure from tanning beds, there are two things to be aware of:
- UV dosage – One erythemal dose (a fancy term for one tanning session coined by the FDA) equates to the amount of time it takes a tanning device to produce erythema or the slight pinkening of the average person’s skin. Once you have obtained erythema, you have obtained a safe dose of UV rays, which will yield to an optimal dose of vitamin D3.
When it comes to the erythemal dose, the same principle regarding skin type applies. If you are light-skinned, start with the lowest recommended dose or time to avoid being burned. It is also important to take note of the strength of lamps.
The FDA also recommends waiting 24 to 48 hours between tanning sessions because it will take at least 24 hours for the erythema to disappear. With the FDA’s exposure schedule (described as controlled sunshine), you will be able to receive ample sun exposure while indoors.
- EMFs – One reason why tanning beds are deemed dangerous is due to electromagnetic fields (EMFs) that can contribute to cancer. Beds that emit EMFs are those with magnetic ballasts; you’ll determine if the bed is using this type of ballast if you hear a loud buzzing noise while using it. Beds that use electronic ballasts will not have the loud buzzing. I strongly advise avoiding magnetic ballasts, and use beds that have electronic ones.
Proper Vitamin D Supplementation
Dr. Mercola on Vitamin D Testing
If neither sun nor safe tanning beds are feasible, you can go with supplementation. But this is not as simple as taking any vitamin D pill; there are many things to consider.
What your body requires is vitamin D3 and not vitamin D2, the synthetic form commonly prescribed by physicians. One microgram of vitamin D3 or 25-hydroxyvitamin D3 is about five times more potent in raising serum 25(OH)D than an equivalent amount of vitamin D2. Aside from being less effective, vitamin D2 can also pose potential harm to your body.
It is very, very important to have your blood levels of vitamin D tested before and during supplementation. There are two vitamin D tests currently being offered: 1,25(OH)D and 25(OH)D. The correct test to order is 25(OH)D – also known as 25-hydroxyvitamin D – because it is the better marker of overall D status.
Vitamin D Testing with the D*Action Study Measurement Kits
At Mercola.com, we offer vitamin D measurement kits courtesy of the D*Action study. The D*Action Project was initiated by GrassrootsHealth and is a worldwide project that aims to end the vitamin D epidemic by raising awareness on vitamin D testing (you can find out more about GrassrootsHealth and the D*Action Study in the resources provided below).
At the moment, the D*Action Project is looking for study participants, and you can be one of them. All you need to do is to purchase the D*Action Measurement Kit and follow the registration instructions included.
Using this kit, you can measure your vitamin D levels twice a year during a five-year program. Once you do, your health status will be shared to demonstrate the real significance of vitamin D.
Take note that 100 percent of the kit proceeds will go to the D*Action study. We also cannot ship these kits to the state of New York, because the their health department regulations prohibit their citizens to send dried blood post cards outside of the state.
Below is a chart showing the ideal therapeutic levels of vitamin D you’ll want to reach and maintain:
There is a risk of overdosing on a vitamin D supplement that doesn’t exist with natural sun exposure, as your body simply stops producing vitamin D to prevent this. You need to consciously keep your vitamin D levels within the healthy range through regular vitamin D blood tests, and have your dosage adjusted accordingly.
Below are my vitamin D dosage recommendations for different age groups:
Vitamin D Dose Recommendations
35 units per pound per day
Age 5 - 10
There is no way to know if the above recommendations are correct for you personally, as they are only guidelines. The ONLY way to know is to test your blood. You might need four to five times the amount recommended above. Ideally, your blood level of 25(OH)D should be 60ng/ml.
Vitamin D Resources
In addition to my vitamin D lecture and the information posted above, below are resources that will help you further understand the importance of vitamin D, and educate yourself about the growing vitamin D deficiency problem.
Top Vitamin D Articles on Mercola.com
The following articles provide information and updates on vitamin D research, as well as my recommendations on optimizing your vitamin D levels:
- My One Hour FREE Vitamin D Lecture
If you prefer to read your information rather than watch it, I've summarized the most important points of my vitamin D lecture in this article.
- Important Vitamin D Update
How does vitamin D impact your overall health? What factors affect your risk for vitamin D deficiency? Discover the answers in this article.
- Vitamin D is a Key Player in Your Overall Health
Find out what diseases vitamin D favorably influences.
- Avoid Flu Shots With the One Vitamin that Will Stop Flu in Its Tracks
Why expose yourself and your family to the dangers of an ineffective vaccine when the solution is right outside your door?
- Vitamin D Journal Articles
Take a look at this compilation of references proving the super-nutrient properties of vitamin D.
- The Amazing Wonder Nutrient That May Prevent or Cure Seven Common Diseases
Did you know vitamin D deficiency has been linked to cancer, diabetes, osteoporosis, rheumatoid arthritis, inflammatory bowel disease, multiple sclerosis and autism? Find out more on my FREE special report.
- Why the New Vitamin D Recommendations Spell Disaster for Your Health
How could the FDA conclude that the vitamin D needs of pregnant women and adults are the same as those of infants and children? Discover the more appropriate dosage recommendations from Dr. John Cannell and Carole Baggerly of GrassrootsHealth.
- Pregnant? Why You Need to DEMAND This Test...
A study finds that women who develop a severe form of pregnancy-related high blood pressure tend to have lower blood levels of vitamin D.
- Why You Don't Want to Rely on Fortified Foods
Is obtaining vitamin D from dietary sources sufficient to optimize your levels?
- This Vitamin D Supplement Mistake Raises Your Death Rate by 2%
Why is vitamin D2 inferior to vitamin D3? This article will give you the lowdown on these two types of supplements.
- The Vitamin that is Better than Fluoride in Reducing Cavities
Aside from influencing your bone health, vitamin D can also greatly contribute to your oral health.
- New Study Shows This Vitamin Helps Prevent Depression
Women with the highest intakes of vitamin D were significantly less likely to suffer from depressive symptoms.
- The Wonder Vitamin That May Help You Prevent 16 Types of Cancer
Theories linking vitamin D deficiency to cancer have been tested and confirmed in more than 200 epidemiological studies, and understanding of its psychological basis stems from more than 2,500 laboratory studies.
- Little Sunshine Mistakes that Can Give You Cancer Instead of Vitamin D
What constitutes safe sun exposure? Read this article to learn about my recommendations for safe sun exposure.
- Are You Making These Sunshine Mistakes?
While discussions about the health benefits of sun exposure typically center around vitamin D, UVB exposure has a number of other health effects unrelated to vitamin D production, including mood and energy enhancement and the treatment of skin diseases.
- Surprise! Vitamin D Can Help or Hinder Your Weight Management
A study of more than 4,600 women age 65 and older shows that having low vitamin D levels can contribute to mild weight gain.
- What You Need to Know About Vitamin K2, D, and Calcium
Discover the interplay among vitamin K2, vitamin D, and calcium in this breakthrough discovery.
- 3 Reasons You May Not be Getting Enough Vitamin D this Summer
How are mainstream health warnings about the dangers of sun exposure contributing to the vitamin D deficiency problem? It’s time to learn the truth about sun exposure and vitamin D.
- This Everyday Outdoor Mistake Can Make You a Magnet for Melanoma
Learn the toxic truth about most of the sunscreens on the market today, and the actual benefits of appropriate sun exposure.
- This Vitamin Found to Rejuvenate Aging Eyes
Research shows that vitamin D3 is a potent tool in promoting healthy vision.
- Ignore This Deficiency... And Become 3 Times More Likely to Die?
Addressing vitamin D deficiency can slash your risk of premature death by more than half, according to a recent analysis.
- The Vitamin That Has Been Shown to Dramatically Improve Fertility
Recent research has revealed the link between low levels of vitamin D and infertility.
- How Vitamin D Can Help Slash Your Risk of 7 Different Acute and Chronic Diseases
Studies are showing how vitamin D -- combined with proper strength training exercises -- can help slash your risk of certain diseases.
- How Vitamin D Performance Testing Can Help You Optimize Your Health, and Aid the Health Freedom Movement
The D*Action project has been initiated by GrassrootsHealth and 42 leading vitamin D researchers to demonstrate how health can be achieved with what’s known about vitamin D through a combination of vitamin D measurement and health outcome tracking.
- Healthier Alternatives to the Seasonal Flu Vaccine: Garlic, Zinc, and Vitamin D
These natural remedies just might be what you need to protect yourself during the cold and flu season in the US.
There are myriads of other resources on vitamin D on the World Wide Web. Aside from providing updates on vitamin D research, these sites will also introduce you to researchers and organizations with valuable work in raising vitamin D awareness.
- Sunlight, Nutrition and Health Research Center
(SUNARC) – An organization dedicated to research and education associated with disease prevention through lifestyle changes.
- Vitamin D Council Website
The Vitamin D Council aims to raise awareness among the general public on the growing vitamin D deficiency pandemic and the benefits of sun exposure.
Founded by Carole Baggerly, GrassrootsHealth is the vitamin D research organization that pioneered the D*Action Study, a worldwide public health campaign that aims to end the vitamin D deficiency epidemic by means of raising awareness on proper vitamin D testing.
- Dr. James E. Dowd, MD
Author of The Vitamin D Cure and founder of the Arthritis Institute of Michigan, Dr. James Dowd specializes in integrative holistic medicine, adult rheumatology, and pediatric rheumatology and has been practicing for more than 20 years.
This page provides basic information about vitamin D, as well as details the work of its creator, nutritionist Krispin Sullivan, CN.
- Vitamin D at OrganizedWisdom™
This vitamin D resource page offers vitamin D information and other links that can raise awareness about this nutrient.
- 2013 Vitamin D Webinar Series | DiaSorin
This resource provides a schedule of 2013 vitamin D webinars conducted by experts.
Presentations and Lectures
Get the lowdown on vitamin D benefits and vitamin D deficiency from the experts themselves. This section provides resources from lectures and presentations on vitamin D held in recent years.
- The Vitamin D Pandemic and its Health Consequences
This lecture is presented by Dr. Michael Holick, PhD, MD, professor of medicine, physiology, and biophysics, and director of the General Clinical Research Center at Boston University Medical Center.
- Diagnosis & Treatment of Vitamin D Deficiency
The University of California, San Diego held this seminar series on vitamin D this last April 9, 2008. You can access the lecture slides of each vitamin D expert on this resource page.
- Prospects for Vitamin D Nutrition by Dr. Reinhold Vieth
This resource provides Dr. Vieth’s lecture on vitamin D nutrition, as well as presentations by other experts on related health topics.
- Vitamin D Scientists’ Call to Action Statement
Created by scientists from GrassrootsHealth, this statement discusses the compelling link between vitamin D and cancer, along with information on oral vitamin D supplements.
- Vitamin D and Prevention of Chronic Diseases
Here's a lecture by vitamin D expert, Dr. Michael Holick, PhD, MD, discussing the relation of vitamin D to bone and muscle health and the prevention of autoimmune and chronic diseases.
In this section, I have provided a list of books and reports that will help educate you about latest findings about vitamin D nutrition – specifically about vitamin D deficiency prevention and sunlight exposure.
- Dark Deception: Discover the Truth about the Benefits of Sunlight Exposure
By Joseph Mercola with Jeffry Herman
Enlighten yourself on the growing epidemic that is vitamin D deficiency, as well as methods that will help optimize your vitamin D levels.
- Solar Power for Optimal Health
By Marc Sorenson, foreword by William B. Grant
How will vitamin D and sunlight save your life? This book will provide you with the answer, plus other information on vitamin D’s role in disease prevention.
- The Vitamin D Cure
By James E. Dowd and Diane Stafford, John Wiley & Sons
This phenomenal book discusses breakthrough research about the causes of vitamin D deficiency, and reveals a five-step program that can aid in disease prevention and your overall health.
- Naked at Noon: Understanding Sunlight and Vitamin D
By Krispin Sullivan (Available through her website)
Nutritionist Krispin Sullivan discusses sunlight exposure as a means to optimize vitamin D levels, and other important details that even medical practitioners are yet to know.
- Sunlight Robbery
By Oliver Gillie (Available through his website)
How is sunlight exposure good for you when the media and government promote it as unsafe and cancer-inducing? Sunlight Robbery will clear up misconceptions about sun exposure and provide you strategies that will help you address low vitamin D levels.
- Scotland’s Health Deficit: An Explanation and a Plan
By Oliver Gillie
This report by Oliver Gillie tackles the vitamin D deficiency problem in Scotland and how this problem is given very little attention by the government.
- The UV Advantage
By Michael F. Holick and Mark Jenkins
Too much sunshine may cause health issues, but a lack of it puts you at risk for vitamin D deficiency. This book provides the benefits of exposure to sunlight – despite mainstream myths and misconceptions.