Boost Vitamin D, Reduce Cancer

Boost Vitamin D, Reduce Cancer

Julian Whitaker, MD

In July 1974, Cedric and Frank Garland drove from San Diego to Baltimore, where Cedric had taken a teaching job at Johns Hopkins University and his brother Frank was working on his PhD. A few days after they arrived, they happened to attend a lecture where National Cancer Institute maps were presented that showed county-by-county death rates from various types of cancer. Each county was color coded in blue, indicative of the lowest rates, or, in increasing order of magnitude, white, orange, or red, for the highest.

The maps looked like someone had drawn a horizontal line across the middle of the country. Except for spotty patches here and there, the southern half of the United States was blue and the northern half was white—except for the Northeast, which was lit up like a Christmas tree. The map for colon cancer was particularly striking. Death rates were twice as high in the Northeast as in the Southwest.

The prevailing thought at the time was that red meat caused colon cancer, but these geographic differences were so startling that the Garland brothers figured it had to be something else. This became the focus of their research, and, in 1980, they published a groundbreaking paper entitled “Do Sunlight and Vitamin D Reduce the Likelihood of Cancer?”

At the time, they were met with scorn and ridicule. But they persevered, and today vitamin D deficiency is widely recognized as a major risk factor for cancer.

The Cancer–Vitamin D Connection

A plethora of epidemiological, lab, and clinical research reveals that people with low blood levels of vitamin D are much more likely to be diagnosed with and die of cancer than those with higher levels. The strongest and best-studied associations are with colon and breast cancer, but robust relationships have also been observed for 17 different types of cancer, including endometrial, kidney, ovarian, and non-Hodgkin’s lymphoma. Research suggests that if everybody maintained even moderate levels of vitamin D, worldwide deaths from many common cancers could be cut by 50–75 percent!

At the recent Diagnosis & Treatment of Vitamin D Deficiency conference, where experts from around the world gathered to share the latest findings, Dr. Cedric Garland explained that vitamin D is required for the production of proteins called cadherins. These proteins allow cells within tissues and organs to adhere together, communicate with one another, and function as a unit. When there’s a vitamin D deficiency, the junctions between the cells are disrupted, and this, according to Dr. Garland, is the true genesis of cancer.

DNA damage is, of course, a factor. However, our genes take hits all time, but the damage and the aberrant cells that are produced are usually destroyed, repaired, or contained. Only when insufficient vitamin D loosens up the intercellular junctions and impairs the cells’ ability to work together and keep the bad guys under control do real problems begin. And once rapidly dividing cancer cells gain a toehold, they beat out normal cells in the competition for nutrients and other resources. Over time, tumors form, malignant cells work their way through gaps in the basement membrane (the layer of cells that lines the inner and outer surfaces of the organs and blood vessels), and metastasis is underway.

At any point in this process, vitamin D can intervene. An optimal blood level protects against cancer by maintaining tight intercellular junctions. If cancer is already present, vitamin D helps to restore normal cell growth, slow the replication of cancer cells, and promote apoptosis (cell death). It also stops the destruction of the basement membrane, which is the first step in metastasis.

Let the Sunshine In—and Take Supplements

More than half of the world’s population is vitamin–D deficient. Don’t be one of them. Start by getting out in the sun for 10 to 15 minutes every day between 10:00 and 2:00—or longer if you’re obese or have dark skin. (Do not use sunscreen during this time, as it blocks the UVB radiation that stimulates vitamin D production in the skin, but it is a good idea to wear a hat.)

Unfortunately, sun exposure may not be enough. As the Garlands discovered 30 years ago, geography plays a tremendous role. People in areas with poor air quality are more vulnerable because pollution, especially sulfur from soft coal, blocks UVB (which explains why the Northeast has the highest cancer rates). Most important, however, is latitude. If you live at 37 degrees north latitude—the “waistline” of the US—or higher, the oblique angle of the sun prevents UVB rays from hitting the earth during the fall and winter. Therefore, the only predictable way to boost levels is to take vitamin D supplements.

Help Spread This Important Message

Enlightened consumers are getting this message. Sales of vitamin D have quadrupled in recent years, and even WalMart sells supplements that contain 5,000 IU. But has your physician recommended a vitamin D blood test? Do public policymakers promote awareness? On the contrary, these dinosaurs continue to over-promote sunscreen use, warn about the dangers of high-dose vitamin D, and maintain the tired old RDAs of 400 IU for people in their 50s and 60s, 600 IU for those over 70, and 200 IU from infancy through age 50. How could anyone believe that the same amount would suffice for a seven-pound baby and a 200-pound man—particularly such an inadequate dose as 200 IU!

Vitamin D deficiency is a very serious problem that also increases risk of cardiovascular disease, osteoporosis, autoimmune disorders, immune dysfunction, and a host of other health concerns. Just imagine the strides we could make in lowering cancer rates and overall disease burden by tackling this risk factor, which can easily be reversed with an inexpensive nutritional supplement.

You likely know your weight, blood pressure, and cholesterol levels. You should also know your vitamin D level and make sure it’s in the optimal range. It’s that important. Act on it.


  • Have your blood level of vitamin D (25(OH)D) tested and take enough supplemental vitamin D3 (cholecalciferol) to bring it into the optimal range of 50–70 ng/mL. To purchase a mail-order test kit, call (800) 810-6655.
  • Because there is no one-size-fits-all dose, I’m reluctant to give a specific dosage. However, if pushed, I would recommend daily vitamin D3 doses of 1,000 IU for infants, 2,500 IU for preteens, and 5,000 IU for adolescents and adults, with regular blood tests for all. Vitamin D3 is exceptionally safe and well tolerated.
  • To learn about the nutritional therapies offered at Whitaker Wellness for immune enhancement of patients dealing with cancer, call (866) 944-8253.


  • Garland CF, Garland FC. Do sunlight and vitamin D reduce the likelihood of colon cancer? Int J Epidemiol. 1980 Sep 9;9:227–231.
  • UC San Diego School of Medicine. Diagnosis & Treatment of Vitamin D Deficiency Conference: 2010 April 9; La Jolla, CA.

Modified from Health & Healing with permission from Healthy Directions, LLC. Photocopying, reproduction, or quotation strictly prohibited without written permission from the publisher. To subscribe to Health & Healingclick here.

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