The Creator provided all living things with an immune system that is charged with protecting them. I imagine that like a platoon of soldiers charged with defending me, and I have to make sure they don’t run out of ammunition. That ammunition is comprised of specific nutrients we must provide the body in order for it to function optimally and avoid disease.
There are 4 main nutrients, which based on my research, I consider essential for maintaining a strong immune system and preventing the development of cancer. As I have said before, cancer is a result of a breakdown in your body’s defenses, not something you catch like a cold or flu. So if you keep your defenses strong, your chances of staying cancer free are bolstered. These are vitamin D, vitamin K, iodine and omega 3 fatty acids. Based on my findings, I believe having adequate levels of these four nutrients may reduce the risk of cancer by close to 90%.
My “favorite”, and probably one of the most inexpensive and effective tools in cancer prevention is vitamin D. As I explained in the section on nutritional deficiencies, vitamin D controls about 10% of all genes’ expression, which is huge; when combined with vitamin K, together they control about 20% of our genes. Optimal therapeutic serum vitamin D level is between 60 and 100 ng/mL.
Studies have been done and are ongoing to confirm the role of vitamin D in reducing the risk of 17 different types of cancer, including colon, breast, prostate , ovarian, esophageal, kidney, and bladder cancers. Moreover, researchers are finding that vitamin D improves treatment outcomes in people already diagnosed with cancer. A recent review article estimated that 50,000-70,000 Americans die prematurely from cancer each year due to insufficient intake of vitamin D. 
Colorectal cancer, the second leading cause of cancer death in the US, has been extensively studied in relation to vitamin D and a 50% reduction in risk is shown for people with moderate to adequate levels of vitamin D. An epidemiological review conducted in 2005 at Harvard Medical School once again highlighted vitamin D’s protective effects against colorectal cancer. The Harvard study noted that a person’s vitamin D status at the time of cancer diagnosis and treatment may influence survival.
Next comes a less well known, but equally important nutrient, vitamin K. Most people know nothing about it, some know it is involved in blood coagulation, but fewer still are aware of its remarkable anti cancer properties.
Cancer development happens in stages. It is not within the scope of this article to describe each one, however, we will highlight a few of them to illustrate how vitamin K is intricately involved in preventing each stage (and conversely, a deficiency of vitamin K can allow for cancer development).
Three of vitamin K’s synergistic anticancer mechanisms have recently been identified. Vitamin K3 inhibits DNA-building enzymes. Vitamins K2 and K3 block new blood vessel formation essential to support the rapid growth of tumor tissue.  And vitamin K3 disrupts crucial intracellular communications networks composed of microtubules, preventing the cells from proliferating in a coordinated fashion.
Vitamin K is a carboxyl group donor, essential for many biochemical reactions. It is not toxic at any level, except when used together with the blood thinner Coumadin (Warfarin).
Next on our list is the micronutrient iodine. Popularized by iodized salt, most people are at least familiar with its existence thanks to the government’s efforts to reduce the incidence of goiter by adding it to our table salt. Unfortunately, iodized salt is a pretty unreliable source of our daily iodine requirements. Just as with vitamin D, which is needed in fairly small amounts to prevent rickets, but in far larger amounts to perform all its other immune related functions, the amount of iodine needed for prevention of goiter is only the bare minimum and about 35 times more is needed to achieve adequate levels.
Iodine is essential for the making of the thyroid hormones, T3 and T4. These hormones affect almost all the cells in the body and adequate hormone production is impossible if we don’t have enough iodine to produce them. This can lead to a whole host of diseases, appropriately called “Iodine Deficiency Disorders”
When it comes to cancer, iodine plays an important role in protection against breast cancer and stomach cancer. This can be applied to other cancers as well. Iodine has been shown to protect against oxidative damage from many different chemicals and shows powerful antioxidant properties. When there is a deficiency of iodine, the damage caused by this type of oxidation is one of the early causes of cancer development.  
There is one more important reason why iodine deficiency diseases are so prevalent. Chlorine and fluoride are added to drinking water in most areas of the US and other countries, and fluoride is also found in tooth care products. In addition, bromine is added to most bakery-made baked goods. These elements are all part of the same halogen group on the periodic table (remember high school chemistry?), and all compete for the same receptors in your body as iodine. When the body takes up fluoride, chlorine or bromine instead of iodine, your body’s requirements for iodine cannot be met and that creates fertile terrain for disease.
Essential Fatty Acids
Last on our list, but definitely not least, are essential fatty acids, which have become increasingly popular and recognized as omega 3, omega 6 and omega 9. They are the most important part of each cellular membrane in charge of controlling what goes in and what comes out of a cell. When there is an imbalance in the fatty acids, the fluidity of the cell membrane is affected in such a way as to restrict the flow of oxygen into the cell, causing hypoxia (lack of oxygen), one of the main causes of cancer. Most of the commercially produced oils are high in omega 6 and omega 9, which creates a serious deficiency of omega 3. The proper ratio is 50% omega 3 and 50% omega 6 + 9, and in most cases the actual ratio is closer to 5% omega 3 and 95% omega 6 + 9.
Studies show that omega 3 consumption can delay or reduce tumor development in breast cancer. Studies have also shown that a high blood level of omega-3 fatty acids combined with a low level of omega-6 fatty acids reduces the risk of developing cancer. Daily supplementation with as little as 2.5 grams of fish oils has been found effective in preventing the progression from benign polyps to colon cancer.
Many people are afraid of even tackling the subject of cancer prevention. There are many lifestyle factors that can increase the risk of cancer, such as high consumption of sugar, hydrogenated fats and processed foods in general. Many people find it daunting to even contemplate removing such easy to prepare and tantalizing foods from their lives. And so they simply bury their heads in the sand and hope they will be spared. Cancer prevention is not exclusively dependent on changing your diet. Such changes are important, and I strongly encourage them, but the deficiency of such essential nutrients as vitamin D, vitamin K, iodine and essential fatty acids are far more dangerous. If you are ready to begin with even a small effort, start by adding these essential nutrients to your life. The rest can continue from there, in small steps as you feel ready to try. Your body will thank you.
If you have any questions, please do not hesitate to ask.
 http://www.ncbi.nlm.nih.gov/pubmed/11899952 It is interesting to note that in the study they mention the “problem” with using vitamin D in therapeutic dosages is it can cause hypercalcemia. However, when combined with supplemental vitamin K, the problem can be easily avoided.
 http://www.ncbi.nlm.nih.gov/pubmed/16319673 Notice that in most studies done on nutrients, the language used is “may influence survival” as opposed to definitively saying will influence survival. That helps to repeat studies and receive more funding.
 Life Extension Magazine November 2010