Rico, J. A., Kordas, K., Lopez, P., Rosado, J. L., Vargas, G. G., Ronquillo, D., and Stoltzfus, R. J. Efficacy of iron and / or zinc
supplementation on cognitive performance of lead - exposed Mexican schoolchildren: a randomized, placebo - controlled trial.
The same researchers mentioned in the first study
on creatine above also investigated the effects of creatine
supplementation and sleep deprivation alongside mild exercise
on cognitive performance and bio-motor skills (3).