It is no mystery that vitamin D is an oil-soluble vitamin and in large doses may be toxic. So it should come as no surprise that extremely high levels of vitamin D actually caused prostate cancer, just as very low levels can. Vitamin D can have a reverse effect and when one has very high levels it will actually cause osteoporosis, heart disease, autoimmune problems and cancers.

However, one needs to cautiously interpret these results. I have tested thousands of patients' vitamin D levels, and I have only seen one patient have the high levels. It is important to understand that it is not easy to get high levels of vitamin D without taking very large doses for long periods of time.

By far, the vast majority of people reading this right now have far too little vitamin D in their blood. Over 85 percent of people have levels below 32, which is considered deficient. In my practice we don't like to see patient levels go much above 50, but 55 is probably a perfect level and anything above 60 is likely to be toxic. This study found cancer started to occur at 80. So, be smart and get your vitamin D level tested.

We routinely put people on 10,000 units a day or more of vitamin D safely as long as we monitor them. It is important to understand that most of us get 10,000 units on a sunny summer day if we have significant exposure. Although the RDA of vitamin D is currently 400 units, it will likely change to 4,000 units in the near future.

Along with getting your vitamin D levels tested, an excellent source of vitamin D, which is pivotal in preventing cancer, and many other diseases, is cod liver oil. This is especially important this time of year as most of our vitamin D levels are decreasing due to limited sun exposure. I now offer the Carlson brand of fish oil and cod liver oil in my "Recommended Products" section, or you may be able to find this exceptional quality brand in your local health food store. If you want to learn more about fish oil and cod liver oil please check out my frequently asked questions page on this site.

Related Articles:

Why You Need to Have Your Vitamin D Level Tested Now

Breakthrough Updates You Need to Know on Vitamin D

RDAs of Vitamin D Far Too Low

Odds are You Need Additional Vitamin D, and Cod Liver Oil is Not Sufficient

How Much Vitamin D is Too Much? Take This Vitamin D Quiz to Find Out!

Up to 70 Percent of Americans May be Deficient in Vitamin D--Find Out Why You Don’t Want to be One of Them