Vitamin D Deficiency and Cancer

January 23, 2009 7 min read

Vitamin D Deficiency and Cancer
Dr. Lani Simpson, D.C. Excerpted from her forthcoming book, The Sun Companion

As we are nearing winter months, I am concerned that many of my readers are vitamin D deficient and unaware of it. In this newsletter we will focus on vitamin D deficiency and cancer, risk factors for vitamin D deficiency, vitamin D testing, and options for therapeutic supplementation. Generally, most of us associate vitamin D with bone health. However, vitamin D plays many important roles in our health, including cancer prevention. Studies show that people who live in sunny climates, close to the equator or the southern hemisphere, have significantly fewer instances of breast, colon, and prostate cancer than those who live in northern climates. Congruently, the National Institute of Health recently stated that, “strong biological and mechanistic bases indicate that vitamin D plays a role in the prevention of colon, prostate, and breast cancers.”

Vitamin D has become a hotly debated topic in recent years. Some researchers claim that a billion people worldwide are deficient. Further, some claim that vitamin D deficiency is at epidemic proportions in the United States. After reviewing scores of studies I am convinced that the number of people with deficiency is staggering. Articles and news reports offer a solution: sun exposure on our face and arms for 15 minutes, three times a week. Another stated solution is taking a supplement containing 200-800 IU of vitamin D each day. However, these recommendations are woefully inadequate for most people, and not nearly enough to maintain a healthy level of this vital nutrient.

On December 2nd, I attended a vitamin D conference in San Diego, CA. Many of the top vitamin D experts in the world were on hand reporting on new findings associated with deficiency. I spoke with cancer researcher William Grant, Ph.D., who he said that he has good data supporting vitamin D deficiency involvement in 14 cancers with 13 more suspected. Frank Garland, Ph.D. stated that breast and colon cancer may be reduced by as much as 50% if vitamin D blood levels are maintained on the high end of normal. Prostate cancer had similar results. There is a current trial of men with localized prostate cancer who have elected to forego medications in favor of taking a 6000 IU daily dose of vitamin D. On Wednesday, December 17, 2008 I am offering a free teleseminar to further discuss these exciting new developments and my thoughts on testing and safely raising blood levels of vitamin D.

Vitamin D deficiency became a personal issue for me when I found out that I was deficient seven years ago. I was shocked given that I live in California and like many people I thought that the amount of sunlight I was receiving from my daily walks plus a daily dose of 1,000 IU supplement was enough to maintain a healthy store of vitamin D. However, as I discovered, there are many variables regarding a specific individual’s ability to produce vitamin D from the sun. Once my vitamin D level was normalized, I stopped losing precious bone and other health conditions, including unexplained joint and muscle pain, improved dramatically.

How is it possible that so many people could be lacking in vitamin D and not know it? Why are our health care professionals not more aware of promoting this key component to maintaining health? Simply put, there is a lot of misinformation and lack of education regarding vitamin D. Physicians rarely order the blood test for vitamin D, and when they do, they often misread the findings. If a test falls within the range set for “normal” the vitamin D level is considered normal with no further consideration given. Most if not all vitamin D experts today agree that “normal” is actually closer to the high end of the currently accepted range. Finally, there are two vitamin D tests and sometimes the incorrect test is ordered. For the past seven years I have tested most of my patients for vitamin D status and approximately 9 out of 10 range from serious vitamin D deficiency to insufficiency.

How We Make Vitamin D

Vitamin D is produced when a specific ultraviolet ray (UVB) strikes the skin. The radiation interacts with a form of cholesterol just under the surface, producing vitamin D3 or cholecalciferol. D3 then undergoes two more transformations in the liver and kidneys to become a powerful steroid hormone. The naked body is capable of producing 20,000 IU in one day and will never overdose due to feedback mechanisms that destroy excess vitamin D. It is possible to overdose if one takes vitamin D orally.

Risk Factors for Vitamin D Deficiency

Not just any sunshine will make vitamin D. Only one ultraviolet ray (UVB) will produce vitamin D. It is strongest at noon. In the region where I live, the San Francisco Bay area, UVB rays are not strong enough to produce vitamin D from October through the end of March. Foggy days completely obliterate the vitamin D producing rays. Following are some of risk factors for developing a vitamin D deficiency:

  • Not enough exposure to sunshine when UVB (vitamin D producing) rays are abundant
  • Living in northern latitudes, above San Francisco on the West coast and Richmond, Virginia on the East coast - the farther away from the equator, the fewer UVB rays
  • Darkly pigmented skin – dark skin will need up to 12 times more UVB exposure than light skin to produce significant vitamin D
  • Sun avoidance
  • Daily use of sunscreens or sunblock – (SPF 15 can reduce vitamin D production by 95-99%)
  • Living in foggy and/or smoggy areas – (Fog and smog reduce UVB rays)
  • Indoor jobs, or night-shift work that require sleeping during the day
  • Aging – Skin thins as we age and produces less vitamin D
  • Diets high in processed foods
  • Digestion problems, especially fat malabsorption syndrome
  • Inflammatory bowel disease including ulcerative colitis and Crohn’s disease
  • Cushing’s syndrome
  • Surgical removal of segments of the small intestine
  • Kidney or liver disease
  • Medications including corticosteroids, Proton pump inhibitors, some cholesterol lowering drugs, Dilantin, and Phenobarbital.
  • Living in nursing homes, prisons, or other confined situations
Vitamin D as a Cancer Treatment

While research is strong that vitamin D deficiency plays a protective role against developing many forms of cancer, it is less clear as to whether or not vitamin D can be used to successfully treat cancer. Research indicates that people who have higher levels of vitamin D circulating in their blood when diagnosed with colon, breast, prostate, and lung cancer will have better outcomes and less recurrence of the cancer. Even though it seems counter-intuitive, the most dangerous form of skin cancer, melanoma, too has been linked to vitamin Deficiency. New research in 2008 looks promising that vitamin D may prove effective as an adjunct treatment in breast cancer. Cancer patients should be tested for vitamin D deficiency - and if they are deficient, they should be treated by someone who is familiar with vitamin D testing and treatments.

How the skin produces vitamin D from sunshine

I am including a free 8-minute audio for you to download or just listen to on the website regarding this interesting process.

Vitamin D in a Nutshell
  • Skin production of vitamin D is dependent on skin type, age, geographic location, and atmospheric conditions (fog or smog).
  • Dietary sources of vitamin D are low, including fortified milk which contains a meager100 IU per 8-ounces.
  • Vitamin D testing is strongly recommended for those who want to raise their vitamin D blood levels to a safe and appropriate level with supplementation.
  • Vitamin D is a fat-soluble vitamin. Make sure to take supplemental vitamin D with a meal.
  • Over time, too much vitamin D supplementation may lead to health problems. This is why testing is important.
  • Sensible sun exposure is the safest way to obtain vitamin D. This will be covered in a future article.
  • Supplemental D3 (cholecalciferol) is superior (more stable and twice as potent) to supplemental D2 (ergocalciferol).
Vitamin D Testing

Testing vitamin D is the only way to make sure you have a healthy level of circulating vitamin D in your blood. The home test kit offered below is simple finger prick rather than a venous puncture at a drawing lab. If you want to test your children this is the preferred method by most parents.

  • Testing for vitamin D requires a simple blood test. The cost of the test ranges from $115.00 to $250.00 depending on the lab that you use.
  • The correct test measures 25-hydroxyvitamin D. Make sure your provider orders this exact test.
  • If you are going in to have your blood drawn, have your calcium checked at the same time.
  • You can obtain your test in one of two ways:
    • Your health care provider can order the test from a lab – Lab Corp is currently the best lab because it is using the correct analysis method.
    • You can order a home test kit available from this web site that will include diagnostic information – the cost of this test is $100 and is a good option for those without insurance or a high deductible. It is not covered by insurance.

    To order your vitamin D test kit plus a 20-minute phone consult with Dr. Simpson click here. Dr. Simpson can explain your test and offer advice to help you correct a vitamin D deficiency. It is critical that you know how to balance nutrients with your program to replenish this vital nutrient.

    How Much Vitamin D Should You Take?

    Vitamin D is a fat-soluble vitamin that is stored in the body. In its most active form vitamin D is actually both a hormone and a powerful anti-oxidant. However, vitamin D supplementation should not be taken lightly. Though rare, oral ingestion of vitamin D can lead to toxicity. Vitamin D supplementation must also be combined with a balanced calcium intake, as vitamin D increases calcium absorption by as much as 50%. Elevated calcium in the blood can result in unintended health consequences over time.

    The current governmental recommendations for daily vitamin D supplementation range from 200 to 800 IU, although some people require as much as 4,000 to 10,000 IU each day to increase or maintain a healthy blood level of vitamin D. A blood test is the only way to know for sure if you are deficient or if you are taking too much of this essential nutrient.

    Want to learn more about vitamin D?
    • Join Dr. Simpson, D.C. for a free teleseminar on vitamin D: Wednesday, December 10th, 7:00PM to 8:00PM (PST). She will answer your questions and report on the latest research from the December 2nd Vitamin D Conference.
    • How the skin produces vitamin D: Free 10-minute audio podcast with Dr. Simpson, D.C. on vitamin D.
    • If you would like to schedule an individual appointment in-person or by phone with Dr. Simpson, D.C.