I disagree. Outside of a few specific situations (folic acid for pregnant women, etc.), most first world people satisfy their nutritional requirements. Micronutrients aren't a "if a little is good, a lot is better" situation. Once you meet your daily requirement, you're just passing most of what you take.

Further, of all the science done on CAM (Complementary and Alternative Medicines), only a couple of studies have shown a positive impact.

I don't doubt Kurzweil is a smart guy. However, there are plenty of smart people who have had theories like this. Eg., Linus Pauling and Vitamin C megadose theory. (see wiki for more info).

It may not seem like there's a stretch. But your perception of the logical continuum doesn't really matter. Most supplements are nothing more than snake oil. (Again, assuming you have an otherwise balanced diet).

Also, you have a fallacy -- eschewing certain foods is removing potentially harmful nutrients from your diet. Why would it logically follow that adding something would necessarily confer a health benefit?