If taken in supplement form, just 3 mg a day will not only ward off prostate cancer, but also, according to USDA researchers, is the best dosage to improve memory and concentration. It has also recently been found that spa centers which are famous for curing arthritis have a high boron content in the water. If a man has arthritis you can be sure he needs a supplement of boron.

Fruit and vegetables contain boron, but due to modern agriculture, it has been depleted from the soil, so even with fresh vegetables you may not be getting enough. The best natural sources of boron are raisins and almonds.

Omega 3
Of all the nutrients available, Omega-3 fatty acids delivers the most bang for your buck. A healthy man needs 1000 mg a day to receive the multiple benefits of this fish oil, which include: reduction in pain and inflammation, protection against heart attack and stroke, reduced risk of high blood pressure, improved memory, focus and concentration, and a reduction in the symptoms of depression.

Taking two 500-mg tablets each day is the best way to add these essential fatty acids to a man's daily regimen. They can also be found in salmon, mackerel, sardines or other fatty fish.