Numerous studies clearly demonstrate that vitamin supplementation does not reduce a risk of cancer, heart diseases, dementia, various infections and does not extend the lifespan of healthy humans. On the contrary, there are a few studies showing that synthetic vitamin supplements increase the risk of cancer for smokers.
A comprehensive study, published in Archives of Internal Medicine (2011), revealed a 6 % mortality increase of women using multivitamin supplements. Another study reported a 46 % (!) increase of lung cancer risk in the case of people exposed to cigarette smoke or asbestos connected to vitamin A supplementation. Based on these findings, the study was stopped and for instance Danish government banned selling vitamin-enhanced food.
Further research studies found a link between high vitamin E intake and prostate cancer, or supplementation of calcium with vitamin D and formation of kidney stones and increased frequency of heart diseases, while the promised osteoporosis reduction was not observed.
Unlike pharmaceuticals, vitamins are essential for life, however, in unnatural consumption they should be considered drugs, able to cure, but also harm. Even high doses of vitamin B12, generally considered harmless, can hide some symptoms of various diseases and prevent early treatment.
So why are people willing to spend their money for vitamin supplements? Well, first of all no one is able to escape the intrusive advertisements and product propagation. One might even wonder whether it is possible to live without those miraculous pills and potions. Moreover, it is much more convenient to take several pills a day than to stop smoking, reduce alcohol consumption, lose some body fat, regularly exercise, and keep a diet rich in natural nutrients and vitamins - mostly fruits and vegetables.
There is an agreement among many researchers and doctors that except for the supplementation of folic acid in the case of women planning pregnancy, or vitamin D intake of people without any access to a direct sunlight, the vitamin supplementation is just a waste of money.
A regular vitamin intake is definitely essential, but through the evolution our bodies were taught to extract and use vitamins from natural resources and not from artificial ones. If you want to invest your money wisely, buy fresh high quality food, mostly fruits and vegetables. There is no study questioning the positive impact of a healthy diet on a human organism.