Optimize Your 25-Hydroxy Vitamin D Level To Improve Your Chances of Preventing and Surviving Cancer

Friday Apr 10 | BY |
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Food sources of vitamin D

Vitamin D, the rising star of nutrients, gets even brighter. Scientific research on vitamin D includes more than 62,000 published studies, and more than 800 of these are about controlling cancer.

Research informs us that breast cancer patients who have high vitamin D levels as measured by a blood test survive twice as long as those with lower levels. A study published in 2015 found that even in advanced stage breast cancer, survivors with high vitamin D levels lived longer than those with deficient levels.

A study in the Journal of Clinical Oncology found that higher vitamin D levels improved survival in patients with follicular lymphoma. The same results were found in other cancers, including colorectal cancer, prostate cancer, and ovarian cancer.

Scientific evidence keeps mounting to support that idea that low vitamin D levels contribute to cancer growth, and that optimizing vitamin D levels help prevent cancer and improve chances of beating cancer.

Sun Exposure Is Not Enough

In my patients, I’ve followed the epidemic of low vitamin D levels since 1986. Even in Southern California, where I practiced for 25 years, vitamin D levels were too low. I became suspicious that sun exposure was but one source of vitamin D, and that dietary sources were more important than sunlight. To confirm this idea, I tested patients from India, South America, Mexico, and Australia. I found the same results: low or sub-optimal vitamin D levels.

With concerns about skin cancer risk and accelerated skin aging from overexposure to the sun, people were becoming shade lovers instead of sun worshipers. Applying sunscreen to block UV rays, also prevents vitamin D synthesis in the body.

Natural sunlight remains important for health, but food and supplements are necessary to optimize vitamin D levels.


However, vitamin D is almost exclusively found in animal foods. A 2013 study on vitamin D status in vegetarians found severe deficiency irrespective of sunlight exposure.

Unless vegans consume vitamin D fortified soy and other vegetarian products, they are at high risk for vitamin D deficiency. Another way to help boost vitamin D levels for vegans is eating wild mushrooms and IV light irradiated farmed mushrooms. The solution is to take vitamin D3 supplement. But, first get tested.

Test Your Vitmain D Level

Vitamin D status is measured as Serum 25-hydroxyvitamin D in a blood test. Because of it’s importance for health, many doctors now order a vitamin D test on routine blood testing. You can order it on your own from Life Extenstion Foundation, Direct Labs, PersonaLabs, or Anytime labs.

You can also test your vitamin D level from a drop of blood. Theranos offers quick testing in some states at Walgreens. The Vitamin D Council provides in-home test kits using a dried blood spot.

Vitamin D Clinical Levels

To treat cancer, heart disease, and metabolic conditions get your vitamin D level between 70 and 100. More is not necessarily better. Levels above 125 are associated with adverse effects.

Vitamin D Supplements

Not all vitamin D supplements are the same. I recommend pharmaceutical grade Vitamin D3 in capsules or liquid. Remember, first get tested.

If your 25 Hydroxy D level is below 55, take 2,000 IUs daily. If it’s below 39, take 5,000 IUs daily. If it’s below 30, you need 10,000 IUs daily.

It takes time for vitamin D levels to improve. You won’t notice much change for several months. Retest your level in six months.

Don’t Forget Vitamin K

If you take doses of vitamin D3 above 5,000 IU daily, remember to take vitamin K2. You need extra vitamin K to support calcium metabolism that vitamin D alone can’t do. These two nutrients have synergistic activity in healthy building of strong bones and improve cardiovascular health.

Dr. J. E. Williams


Dr. Williams is a pioneer in integrative and functional medicine, the author of six books, and a practicing clinician with over 100,000 patient visits. His areas of interest include longevity and viral immunity. Formerly from San Diego, he now resides in Sarasota, Florida and practices at the Florida Integrative Medical Center. He teaches at NOVA Southeastern University and Emperor’s College of Oriental Medicine.

Visit Dr. Williams’ Website: https://drjewilliams.com/

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  1. June Hanson says:

    So glad, I, can depend on you, Dr Williams to monitor my blood tests. Keeping Vitamin D3 and Vitamin K2 in healthy range. Correct dosage in supplement form. So many Doctors, still are not doing this. Will tell you, just take some good multiple. Others say, get it in your food. You know, the optimal range for preventive health. There is a big difference, as in taking all supplements. Not just over the counter or guessing online.

    With us living in Florida, year round sunshine, on a pennisular, having to use sunscreen, supplements are of great importance. But then, in climates without much sunshine, importance is even greater.

    Most people think, eating salmon, helps them. Most of our salmon, is farm raised in unclean ponds. Which, by the way, most restaurants serve. It costs less, lacks nutrition. Should be either Sockeye or Coho, from cold, fast moving water.
    What a Difference in taste!

    Really cannot eat enough salmon. Daily Pharmaceutical grade supplements are needed. Monitoring our blood, is of utmost importance. Your Doctor, should be knowledgeable, like you, Dr Williams. Not looking for safe range, but optimal range. It is so worth it to prevent cancer and keep us well.

  2. Patrick S. says:

    Great article. However, there is one thing I’ve wondered for a long time. All studies show the health benefits of optimal vitamin D levels. But have they compared people who are naturally high in vitamin D, i.e. though sunlight and diet, and with no supplementation, to people who were low in vitamin D and then raised their levels through supplementation? To me this is a crucial issue to determine if supplementation does the trick or if we need to get vitamin D from the sun or from our diet.

    In theory, these studies could just mean that people who are healthy in general and for unknown reasons, also have higher vitamin D levels because their bodies are better at assimilating and producing it. In that case, supplementation would raise levels but not protect you against cancer etc. If anyone knows the answer, please let us know.

  3. Dr. (M.D.) John A. McDougall, disagrees with your comments above. He thinks that most supplements including vitamin D actually act as a poison to the body and that you can get more than enough vitamin D from the sun. He further disagrees with the standard being 50 or above and that it`s more like 20. It`s more confusion in the health arena. Being in the sun for large numbers of hours seems to produce a number in the 20s which is one reason why Dr. McDougall says the accepted healthy numbers are wrong and really should be in the 20s, not above 50 which seems to be the accepted healthy number by many heath professions.

  4. Jesse Artus says:

    If you are a vegan I guess you are more commuted your principles than you are your own health. As for vegetarians, just take fermented cod liver oil daily and not only will you get plenty of D but also A as a bonus. You can even get high vitamin butter oil for your K. Drink some raw milk and grass fed butter. Why make everything so difficult with all these studies and experts. Its so easy to get your fat soluable vitamin levels up. Just do what people have done for hundreds of years. Eat the foods your body needs

  5. sue T. says:

    Doesn’t vit K increase the clotting of blood?

  6. the info is so good that i did not know how beneficial vitamin D was until i read your information thanks a million

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