It would be difficult to find a nutrient that has been researched more heavily or has been surrounded by more controversy than vitamin D. Still, the preponderance of evidence implicates vitamin D in the prevention of cancer, stroke, osteoporosis, Parkinson’s, Crohn’s disease, fibromyalgia, arthritis, and even cold and flu.
The fact that most of the debate centers around how much to take can be attributed to a misunderstanding of the way our bodies absorb and assimilate vitamin D. For starters, there is a common belief that we can get all of the vitamin D we need from sun exposure. The problem with this notion is that there are several factors that influence how much vitamin D we actually get from the sun. To name a few: the part of the world we live in (above or below the equator); our individual cholesterol level; whether we wear sunblock or sunscreen; and the pigment of our skin. Interestingly enough, cholesterol is absolutely essential for converting the UVB rays of the sun to vitamin D in our bodies. This means that if your cholesterol is below normal, that conversion is less likely to happen. The fact that cholesterol can be too low is a whole other discussion.
Perhaps even more interesting is that vitamin D is not a “vitamin” at all. It is a steroidal hormone. And this is important because it means that it is much more intricately connected to our immune system, pain management systems, and our endocrine systems than we have been led to believe. It is one of the reasons that cholesterol (another hormone) is so essential to its metabolism. It is also why vitamin D has such a positive influence on our immunity.
So back to the original question: How much do we need? Dr. John Cannell is considered the world’s leading authority on vitamin D as he has conducted extensive research on the nutrient and most of his work has been meta-analysis—the study of groups of studies. Dr. Cannell says that ideal blood levels for vitamin D should be in the range of 50-70 ng/ml for healthy people and 70-100 for cancer patients.
So how do you get to those levels? Well since most of us here in North America don’t get enough from mere sun exposure, even in the summer months, we must rely on dietary sources. This includes food and supplements. The only significant sources of vitamin D from food sources are fatty, cold water fish, free range eggs and dairy, and organ meats. The problem with the fish source is that if you eat too much fish, you get more toxic mercury. The problem with the dairy source is the pasteurization process denatures most of the proteins and fats in the milk, thereby rendering it “utterly” useless by the human body. So unless you’re drinking lots of raw milk…..And who eats a lot of organ meats anyway? So essentially most of us have to supplement with vitamin D to get enough.
Ideally, before supplementing with D, it’s a good idea to have your blood tested to see where you are. The proper test to ask for is the 25(OH)D test. If you are one of the 95% of us who aren’t already supplementing with D are below that range, Dr. Cannell says it is generally safe to take as much as 10,000 IU’s daily. It is recommended to begin with 5,000 IU’s daily. And the form you want to supplement with is vitamin D3, or cholecalciferol. The best two sources of this are an emulsified version of D3 or cod liver oil. You want the emulsified version because vitamin D is a fat soluble vitamin and therefore is best absorbed when dispersed in a fatty acid. Cod liver oil happens to naturally contain vitamin D and the cod liver itself is made up of omega 3 fatty acids. The average adult would start with two tablespoons of cod liver oil daily to get 5,000 IU’s. If you don’t tolerate that much cod liver oil (reflux or bowel issues), try cutting it with lemon juice, which breaks down the fat for you. If you don’t take cod liver oil, the best source is an emulsified liquid version of D3.
I hope that clears up some confusion about this most essential nutrient.