Supplements as generally understood include vitamins, minerals, fiber, fatty acids, or amino acids, among other substances. U.S. authorities define dietary supplements as foods, while elsewhere they may be classified as drugs or other products. There are more than 50,000 dietary supplements available. More than half of the U.S. adult population (53% - 55%) consume dietary supplements with most common ones being multivitamins.
Wind power capacity has expanded to 369,553 MW by December 2014, and total wind energy production is growing rapidly and has reached around 4% of worldwide electricity usage.
Wind energy is a clean source of energy that can be produced domestically. Being fueled by the wind, wind energy does not pollute the air or produce any atmospheric emissions. The main challenge facing wind energy is the intermittence of wind and the wind does not always blow when power is required.