08 July, 2011
Functions and Sources of Vitamins and Minerals
Vitamins and minerals are chemical compounds needed for proper functioning of the human body. There are two types of vitamins: fat-soluble and water-soluble. Fat-soluble vitamins -- A, D, E and K -- dissolve in fat and can be stored in the body. Water-soluble vitamins -- B-complex and C -- dissolve in water. Minerals are inorganic elements. Vitamins and minerals have specific functions and are derived from a variety of food sources.
Vitamin A is responsible for promoting vision, bone growth, tooth development, immunity, cell reproduction, formation of hormones, and maintenance of healthy skin, hair and mucous membranes. The retinol form of vitamin A is found in animal products such as liver, milk and eggs, while beta-carotene is abundant in plant foods, including carrots, sweet potatoes, mangos, spinach, pumpkin and apricots.
Vitamin D is known as the sunshine vitamin because it is produced by the body after exposure to sunshine. Vitamin D is found in dairy products, fish, sunflower seeds and egg yolks; however, very little vitamin D is needed from dietary sources if sufficient vitamin D is absorbed from sunlight. Vitamin D not only strengthens bones, but also is necessary for the absorption and maintenance of calcium and magnesium in the body.
A natural antioxidant, vitamin E protects body tissues from oxidative damage. It is also important in the health of red blood cells and the use of vitamin K. It aids in healing, prevention of scarring, and it soothes broken or stressed skin tissue. Green leafy vegetables, wheat germ, whole grains, nuts and vegetable oils are good sources of vitamin E.
Abundant in milk, liver, wheat bran, nuts and a variety of fruits and vegetables, vitamin K regulates blood calcium levels and activates proteins involved in bone health. The primary function of vitamin K is its crucial role in the blood clotting process. Vitamin K aids blood clot formation, stopping bleeding when necessary.
B Complex Vitamins
The B complex vitamins consist of thiamine, or B1; riboflavin, or B2; niacin, or B3; pantothenic acid, or B5; pyridoxine or B6; biotin, or B7; folate, or B9; and cobalamin, or B12. Each of these B vitamins serves different functions, including energy production from food, growth, red blood cell production, formation of hormones, antibody creation, central nervous system function and metabolic processes. Nearly all foods contain B vitamins, especially animal products.
Vitamin C plays a significant role as an antioxidant, protecting the body from tissue damage by oxidation. Free radicals, which are byproducts of normal metabolism and environmental factors, cause cellular damage, leading to disease and illness. Antioxidants stabilize free radicals, preventing damage to the body. Vitamin C is also required for healthy skin, bones, cartilage, teeth, gums, blood vessels, production of collagen and iron absorption. Red berries, kiwi, bell peppers, tomatoes, broccoli, spinach, guava and citrus fruits are excellent sources of vitamin C.
Primarily found in dairy, soy products and green leafy vegetables, calcium is necessary for building strong bones, blood clotting, enzyme regulation and blood pressure maintenance.
Iron is an essential component of hemoglobin, a protein responsible for helping red blood cells carry oxygen throughout the body. Iron-rich foods include red meat, pork, fish, beans, lentils, shellfish, soy products and green leafy vegetables.
Found in whole wheat, nuts, seeds, oats, peanut butter, green leafy vegetables and a variety of fruits, magnesium is required for muscle and nerve function. It is also essential for energy production, bone structure, B vitamin activation and calcium balance. Whole wheat, nuts, seeds, green leafy vegetables and fruit are excellent sources of magnesium.
Potassium-rich foods include mango, banana, kale, grapes, spinach, sweet potato, broccoli and dried fruits. Potassium maintains the body’s fluid balance, blood pressure, heartbeat, nerve impulses, muscle function and is needed for proper growth.
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