Vitamins that could help "make us smarter"?
Are there vitamins that make us smarter?

Vitamins are micronutrients required in small quantities for normal human metabolism. Extra high (supra-physiological) doses do not generally result in improved performance. Of course, if one is deficient in certain vitamins (e.g. Vit B-1 deficiency causing Wernicke-Korsakoff encephalopathy), taking a vitamin can restore normal function. However, with adequate access to a normal diet, you are unlikely to be deficient. Commonly cited exceptions include:  


strict vegans (Vit B12)
alcoholics (thiamine (B1), folate)
cultures highly dependent on maize as a staple (niacin (B3))


In people with a normal diet, taking additional vitamin supplements is usually not helpful.* (An exception may be Vitamin D depending on whom you talk to, but this is unrelated to cognitive performance.)

There have been scattered studies showing some benefit of various plant extracts and other “natural” substances. Studies such as this one about Bacopa monniera do demonstrate benefit. However, many such studies are of limited value due to sponsorship by the makers of supplements and publication in journals with questionable quality of peer review. This meta-analysis reviewing the effects of phosphatidylserine, phosphatidylcholine, citicoline, piracetam, vinpocetine, acetyl-L-carnitine, and antioxidants reached a more guarded conclusion:


  for most of the "brain-specific" nutrients we review, some mildly suggestive effects have been found in preliminary controlled studies 


Note that most of the substances discussed thus far are not vitamins but rather amino acids, more complex plant extracts, or &mdash; in the case of caffeine &mdash; a synthetic crystalline xanthine alkaloid. These sorts of things are commonly included in supplements found at health stores. As for vitamins specifically, this large randomized controlled trial found no effect of multivitamin and mineral supplementation on cognitive function.

What component of Cognitive Supplements are active?

The answer is usually caffeine. Caffeine is cheap, widely available, and markedly improves short-term cognitive and physical performance. By modulating adenosine activity in the central nervous system, it improves alertness, prevents impairment in neuro-plasticity associated with sleep deprivation, potentiates synaptic transmission in animal models, and may slow neurodegeneration in certain disease states. 

This review article looked at ”enhancement supplements” containing taurine, guaraná, ginseng, glucuronolactone, B-vitamins, and other compounds  as well as caffeine and concluded:


  there is an overwhelming lack of evidence to substantiate claims that components of [energy supplement drinks], other than caffeine, contribute to the enhancement of physical or cognitive performance.


To your question,


  Are these supplements safe?


You should look at the ingredients. If it is caffeine, the answer is: usually. However, it is not recommended for those with insomnia, anxiety, palpitations, or who are underweight. As for other components of these, you need to read the label and do your research. As mentioned in the footnote, vitamins themselves are not without the possibility of harm at supra-physiological doses. For other components the danger is likely uncertain and under-researched. 




*For those interested in the vitriol around this subject, check out this series of editorials that followed the paper linked above. Quoting the first of these:



   In conclusion, β-carotene, vitamin E, and possibly high doses of vitamin A supplements are harmful. Other antioxidants, folic acid and B vitamins, and multivitamin and mineral supplements are ineffective for preventing mortality or morbidity due to major chronic diseases. Although available evidence does not rule out small benefits or harms or large benefits or harms in a small subgroup of the population, we believe that the case is closed— supplementing the diet of well-nourished adults with (most) mineral or vitamin supplements has no clear benefit and might even be harmful. These vitamins should not be used for chronic disease prevention. Enough is enough.