Re: Vitamin D - a "magic bullet" or overrated ammo?
>- The latest study (which finds that vitamin D supplementation may be useful in preventing colon cancer, but doesn't have an effect on overall cancer mortality, looked at _many_ more cancer patients than the initial study that Sardi is ballyhooing.
I have noted that it is so easy to affect the outcome of studies by using data from selected groups or by using the wrong form of the substance in question. Vitamins A, B12, D, and E are all examples of this. There are multiple forms available for each of these vitamins and these forms vary in effectiveness.
Consider vitamin E, commonly available as alpha-tocopherol. Among those in the know, it has been well established that alpha-tocopherol is the least effective form of vitamin E to take and it has minimal effect on cardiac health. The actual real results come from gamma-tocopherol which is far more expensive so most people do not take it. It should be combined with mixed tocotrienes as well for maximum results. Most studies that show poor results have used alpha-tocopherol alone.
Vitamin B-12 is commonly found in the stores as cyano-cobalamin. This is a far less effective form than methyl-cobolamin which is the only form that can penetrate the blood-brain barrier. Methyl-cobolamin is also more bioavailable in general but is much more expensive.
Vitamin A is one of a group of many carotinoids. In some studies, it has been found to have positive health benefits while in others, it failed to produce results. The studies that fail or that produce poor results often use either a chemically produced vitamin A or a form that is highly purified. This is an indication that one of the other carotinoid cousins of beta-carotinoid is actually more powerful and producing the sought after results. This is why getting your nutrition from natural sources is important.
Vitamin D is also available in different forms and D3 is the most important one to use as it is the most biologically active. Research and studies done using other forms of vitamin D produce poorer results. During the winter months, it is important to take 800 to 1200 units a day of vitamin D3. Even more important, get 15 minutes of sun exposure twice a day preferably early morning and late afternoon.
When it comes down to studies on the effectiveness of vitamins and the personal use of vitamins, the answer is quality, quality, quality.
Whenever possible, get your vitamins from natural food sources.
Otherwise, the best vitamins and suppliments IMHO are from:
USANA
Life Extension Foundation