A multivitamin is needed by most individuals to provide all of the needed vitamin and mineral missing in ones diet to support proper bodily functions on a daily basis. Here are some nutrients that it provides in sufficient levels, which include vitamin A, vitamin D, B vitamins, vitamin C, vitamin E, and Minerals.

Vitamin A, which is important for normal vision, integrity of the skin and those cells lining the inner surfaces of the body, gene expression, reproduction, embryonic development, growth, and immune function, is most commonly found as beta-carotene in a multivitamin. Unless the person supplementing is diabetic, the body can convert beta-carotene into vitamin A as it is needed. Therefore, the risk of vitamin A deficiency is nearly nonexistent, while the daily value for vitamin A is 5,000 IU, although supplementation of up to 25,000 IU of beta-carotene is safe and effective.

Vitamin D has recently become more and more recognized by the greater public. Its main role in human nutrition is the absorption of calcium and phosphorus from the intestinal tract, which therefore promotes the mineralization of the bones. Vitamin D can be made in our body by ultraviolet rays of the sun converting a cholesterol derivative in the skin. The daily value for vitamin D is 400 IU, while a range of 400 to 1,000 IU is a good daily dosage.

The B vitamins are involved directly or indirectly in energy metabolism. Some B vitamins facilitate the energy-releasing actions themselves while others help to build new cells to deliver the oxygen and nutrients which allow the energy pathways to run. The B vitamins are also involved in the function of the nervous system. The daily value of these vitamins differ according to the B vitamin, with the dosage ranging from 10 to 100 mg, and the dosage for folic acid ranging from 400 to 800 mcg/day.

Vitamin C promotes collagen synthesis in the body, offers antioxidant protection against free radicals, supports thyroxin synthesis and amino acid metabolism, strengthens resistance to infection, and helps in the absorption of iron. The daily value for vitamin C is a simple 60 mg, but studies have safely used 500 to 3000 mg/day.

Vitamin E is very valuable and worth taking as a separate supplement to get the best dosage. It helps the body by providing antioxidant protection against free radicals, stabilizing cell membranes, regulating oxidation reactions, and protecting both polyunsaturated fatty acids and vitamin A. It has also been proven in studies that a natural vitamin E is three times more active in the human body than synthetic vitamin E at similar doses.

Minerals have often been overshadowed in importance by vitamins, but the need for them is vital as they are recognized as essential to human nutrition. Important minerals include calcium, magnesium, iron, zinc, copper, iodine, potassium, manganese, selenium, and chromium.

Calcium is necessary for the formation of bones and teeth as well as blood clotting and normal muscle and nerve activity. Adequate calcium helps to maintain good bone health and may reduce the risk for osteoporosis later in life. The daily value for calcium is 1,000 mg but some research suggests that higher doses may be beneficial.

Magnesium is important for muscle and nervous tissue function and helps with the formation of bones and teeth. Supplementing with magnesium may help to reduce indications of bone loss. Research has shown that supplementing with 250 to 750 mg/d of magnesium can help stop bone loss and increase bone mass.

Another important mineral is iron, which transports oxygen in the body and is also makes oxygen available for muscle contractions. It is also necessary for the utilization of energy. The daily value for iron is 18 mg, but if a deficiency is diagnosed doctors may recommend up to 200 mg/day of iron.

Zinc is associated with the hormone insulin, zinc is involved in making genetic material and proteins, immune reactions, transport of vitamin A, taste perception, wound healing, the making of sperm, and normal development of the fetus. The daily value for zinc is 15 mg, but for specific purposes, levels up to 60 mg/day can be recommended for a short time. However, increased zinc levels can lower copper levels, which is responsible for the formation of red blood cells and nerve fibers. Therefore, copper should be added if zinc is being consumed at higher levels.

Other important minerals include iodine, which is essential in regulating metabolic rate; potassium, which helps to maintain normal osmotic pressure of body fluids and the acid-base balance of the body; manganese, which activates enzymes and is involved in fatty acid metabolism and protein synthesis; selenium, which detoxifies products of oxidized fats, and is found in red blood cells; and chromium, which is necessary for the formation of glucose tolerance factor, a complex that works with insulin.

Most generic multiple vitamins found at mass market stores only supply the RDA for vitamins and minerals. When looking for a good multiple vitamins you should buy only name brands and read the label to see that the above mentioned vitamins and minerals are supplied in the recommended doses. If the one you look at doesn't have the above listed potency then move to another brand that does supply what is needed for optimal health.