Diet, exercise and nutrition play an important role in energy levels, so be sure you're covering all your bases. This information is not meant as medical advice.

Energy SourceDaily IntakeAge Group
Siberian ginseng (Eleutherococcus senticosus)100-200 milligrams (solid)all ages
B-vitamins500-1,000 milligramsall ages
Vitamin C500-1,000 milligrams (x3)all ages
Zinc25-50 milligramsall ages
Iron10-20 milligramspremenopausal women only
CoQ1050 to 100 milligrams50 and older
Grains6 to 11 servingsall ages
Vegetables3 to 5 servingsall ages
Fruit2 to 3 servingsall ages
Dairy products2 to 3 servingsall ages
Weight-resistance training3 days per week20-40+ as health allows
Exercise30 minutes a dayall age groups
Yogaonce per weekall ages
Reikionce per weekall ages

— Heather Graham
 

Sources: U.C. Center for Human Nutrition; Mayo Health Clinic; Encyclopedia of Natural Medicine (Prima) by Michael Murray, N.D. and Joseph Pizzorno, N.D.; The American Council on Exercise; The Herb Research Foundation.