Plants and animals synthesize vitamins, which are classified as organic compounds. In contrast, minerals are inorganic elements found in the earth. Vitamins and minerals are essential nutrients because they are required by the body for good health, and must come from dietary sources. Vitamins are either fat soluble or water soluble, and minerals may be macrominerals or trace minerals.
Fat-Soluble Vitamins
The four fat-soluble vitamins are A, D, E, and K. A person may not need to take in these vitamins every day because the body stores them in the liver and in fat tissue. People who take supplements containing large doses of these vitamins risk having them accumulate to toxic levels. Vitamin D, found in fortified milk and dairy products, salmon, sardines and cod liver oil, helps to make adequate amounts of calcium available for the formation and maintenance of bones and teeth. Vitamin E, an antioxidant, comes from vegetable oils, fruits, nuts, grains and fortified cereals. Intestinal bacteria synthesize vitamin K, and it plays a part in the clotting of blood that occurs as part of the process of wound healing. People with night blindness may not be getting enough vitamin A, which helps the eyes adjust to changing levels of light intensity.
Water-Soluble Vitamins
Vitamin C and the eight B vitamins that make up the B complex are water-soluble vitamins. The body does not store them, and excessive amounts pass out of the body in the urine. The B complex vitamins, B-1, B-2, B-3, B-5, B-6, B-7, B-9 and B-12, are all necessary for proper growth and development, and come from foods such as whole grains, fish, chicken, red meat, eggs, milk and green leafy vegetables. Vitamins B-1 and B-2, for example, play a role in the work of enzymes important to the muscles, nerves and the heart. Vitamin B-7 assists in the breakdown of ingested proteins and carbohydrates into usable components, and vitamin B-9 is a part of DNA synthesis and the formation of red blood cells. Vitamin C is a potent antioxidant, and is critical to the synthesis of collagen, a substance needed to form blood vessels, tendons, ligaments and bone.
Macrominerals
The term macrominerals applies to minerals that the body requires in large quantities each day. They include sodium, calcium, phosphorous, magnesium, potassium, chloride and sulfur. For example, the recommended dietary allowance, or RDA, for calcium is about 1,100 mg per day for adults, and good dietary sources include milk and milk products, salmon, sardines and broccoli. For potassium, the RDA for adults is 4,044 mg per day. Potassium helps to control blood pressure and aids nerve transmission and muscle contraction.
Trace Minerals
The body uses only small daily amounts of the trace minerals which include iron, cobalt, zinc, manganese, copper, selenium, iodine, and fluoride. Prominent among these is iron, which is a component of hemoglobin, the oxygen-carrying molecule found in red blood cells. Foods that contain iron include red meat, fish, eggs, dried fruits and poultry.
References
- Centers for Disease Control and Prevention: Nutrition for Everyone: Vitamins and Minerals
- Colorado State University: Fat-Soluble Vitamins
- American Cancer Society: Find Support and Treatment: Vitamin B Complex
- Oregon State University: Micronutrient Information Center: Vitamin C
- MedlinePlus: Minerals
- Healthkey.com: Minerals and their functions and sources
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