One of my forum members on Yahoo told me that she was taking products that included both niacin and niacinamide and wondered if it was safe to take both at the same time. I had to do a little research to find the answer, and what I found was that it appeared to be not only safe in most instance, but perhaps beneficial as well due to the effects that niacinamide has on Phase 1 of the liver detoxification process and niacin has on Phase 2.
"Simply speaking, the body's natural liver detoxification process involves two steps; Phase 1 and Phase 2. A toxin initially enters Phase 1, the P-450 cytochrome system, and is reduced to smaller fragments. These fragments then progress to Phase 2, where they are bound to molecules such as glutathione, glycine and sulfate. This process creates a new non-toxic molecule that can be excreted in the bile, urine or stool.
In effect, Phase 1 either directly neutralizes a toxin, or modifies the toxic chemical to form activated intermediates which are then neutralized by one of more of the several Phase 2 enzyme systems. In Phase 1, a toxic chemical is converted into a less harmful chemical. This is achieved by various chemical reactions (such as oxidation, reduction and hydrolysis), and during this process free radicals are produced which, if excessive, can damage the liver cells. Antioxidants reduce the damage caused by these free radicals. If antioxidants are lacking and toxin exposure is high, toxic chemicals become far more dangerous. Some may be converted from relatively harmless substances into potentially carcinogenic substances.
One or both detoxification phases can be inefficient or overloaded. A particularly damaging combination in an ill person is an excessive overload of toxins coming into Phase 1, with an inefficient Phase 2. In some cases this combination is believed to be the cause of marked environmental sensitivities, drug intolerances and interactions that characterize many chronic fatigue and fibromyalgia patients."
Niacinamide slows down phase 1, while niacin speeds up phase 2. Niacin is also known as inositol hexanicotinate, vitamin B3 and nicotinic acid.
As an interesting aside, there was a study last year at I believe Caltech Berkley, where they used high doses of niacinamide with 100% success in reversing the rodent equivalent of Alzheimer's. Naturally, the researchers cautioned against anyone trying to do the same thing with humans and of the dangers of taking supplements - despite the fact that niacin and niacinamide have a virtual 100% safety record. I believe that the proper interpretation was to not take any such supplements until they can produce a patentable version to market.