We all need to maintain a healthy level of vitamin D. Agreement on this matter is not uniform among all scientists. For example the conservative National Institutes of Health web site cautions that more research is needed to determine whether people with normal vitamin D levels can protect themselves by taking more, adding that "it is premature to advise anyone to take vitamin D supplements for cancer prevention."
In previous blogs we discussed the problem of getting consensus from health professionals about the scientific validity of taking more of any specific supplement. The influential Institute of Medicine sets the guidelines for the daily doses of nutrients. They have been reticent to increase their guidelines for vitamin D intake. This adds to the confusion for all of us.
But the scientists who actually study vitamin D aren't waiting for more results. Dr. Rheinhold Viet a vitamin D researcher from the University of Toronto says "I have been studying D for more than 30 years and the remarkable thing is that it is actually effective. My jaw drops as to why everyone is not taking more D. It drives me nuts."
How much vitamin D should you take? For years the official upper limit for D has been 2,000 IU a day, but a recent review article for the Journal of Clinical Nutrition concluded that vitamin D is not toxic up to 10,000 IU a day. This is a combined total from drinking milk, eating fatty fish and vitamin supplementation.
If you have any doubts about how much vitamin D to take have a simple blood test to determine your level of 25 hydroxy vitamin D. The normal levels are 16 to 74 ng/ml. Vitamin D supplementation may be one of the most important nutritional steps that you can take to improve your health and longevity.