Nutrition is defined as a biological process in animals and plants involving the intake of food and its subsequent assimilation into the tissues. From the 20th century scientists have identified different nutrients, which constitute the food and have defined nutritional standards and recommendations in order to prevent deficiencies and to promote human health. Nutritional supplements are defined as concentrated sources of nutrients or other substances with a nutritional or physiological effect that supplement the normal diet. At the beginning of the 21st century, increase life expectancy has emerged as new preoccupation for industrial countries and for nutritional science, which one of the challenges is to offer new strategies to improve the quality of human life.1 In this context, nutritional supplements may be used to optimize diet and consequently to improve quality of life. Increased life expectancy is also associated with a need to appear healthy and handsome. Beside the traditional use of topical care, nutritional supplements have emerged as a new strategy to improve skin beauty.
What is a dietary supplement?
As defined by Congress in the Dietary Supplement Health and Education Act, which became law in 1994, a dietary supplement is a product (other than tobacco) thatis intended to supplement the diet;
contains one or more dietary ingredients (including vitamins; minerals; herbs or other botanicals; amino acids; and other substances) or their constituents;
is intended to be taken by mouth as a pill, capsule, tablet, or liquid; and
is labeled on the front panel as being a dietary supplement
Today's dietary supplements include vitamins, minerals, herbals and botanicals, amino acids, enzymes, and many other products.
If you don't eat a nutritious variety of foods, some supplements might help you get adequate amounts of essential nutrients. However, supplements can't take the place of the variety of foods that are important to a healthy diet. There are different types of dietary, or nutritional, supplements. Vitamin and mineral supplements are types of dietary supplements containing micronutrients meant to help a body function smoothly and improve mental health. Herbal (or botanical) supplements are dietary supplements that have a medicinal purpose. Herbal supplements generally support a specific area of the body’s health, such as the liver, bones or skin.