Nutritional supplements

These supplements are thought to directly improve memory:

Phosphatidyl Serine (PS)

PS can boost brain cell function and help turn back the clock on age-related cognitive decline.  Studies show that it can stabilize or even reverse memory loss in those under stress or suffering from early dementia or Alzheimers.  

"With almost 3,000 peer-reviewed research papers available on PS, science has some understanding of how it works.  It is the single best nutrient (really, the single best means of any kind) for safely conserving and restoring crucial higher functions of the brain (what is considered cognition).  The remarkable benefits of PS and its safety in use are now established beyond doubt."  Dr. Parris M. Kidd, cell biologist and authority on nutrition and human health)

Ginkgo Biloba

Improves blood flow, blocks the shrinkage of the hippocampus, acts as an antioxidant (Warning:  thins blood so should not combine with prescription anticoagulant drugs, even aspirin, since might cause internal bleeding)

Choline

Necessary for the production of the neurotransmitter acetylcholine; also important for making cell membranes; also helps lower blood pressure and reduce cholesterol

Acetyl L-carnitine

Improves energy metabolism in the brain's "power plants" (mitochondria); also improves communication between the two hemispheres of the brain (expensive, though)

Indirectly improve memory

These supplements strengthen bodies and minds, allowing memory to function efficiently:

Vitamins (A, B complex, C & E)

Vitamins can be divided into two types, based upon how the body handles them.

Fat-soluble:  can be stored in the liver and fatty tissue for many months; thus, it is easier to acquire a toxic dose (Example:  vitamins A and E)

Water-soluble: can be stored in the body for only a short time and must be frequently replenished (Example:  B complex vitamins and C)

Minerals

Minerals strengthen the nervous system, improving thinking power, overcoming fatigue, etc.

Major minerals (calcium, magnesium) are those the body needs in significant quantity

Trace minerals (zinc, boron, iron, selenium) are those the body requires in small amounts; this does not mean they are unimportant

Keep in mind that the best way to get most vitamins and minerals is from natural foods, because an undesirable buildup is unlikely.  It is not always the case, however, that you can get adequate amounts through normal food intake.  This is particularly true of phosphatidyl serine (PS) and vitamin E.  Natural supplements may prove beneficial in such cases.