What are vitamins and minerals?
Vitamins and minerals are nutrients required in very small amounts for essential body processes. These nutrients act with proteins, known as enzymes, to regulate metabolic processes ranging from the breakdown of sugar and fat for energy to the synthesis of proteins to make the building blocks of various cellular structures.
How much is enough?
A well-balanced diet should provide most people with enough essential nutrients. A well-balanced diet includes eating foods from the four major food groups: dairy products, meat and nuts, cereals and grains, and fruits and vegetables.
The Food and Nutrition Board of the Institute of Medicine has developed Dietary Reference Intakes (DRIs) to make certain that the food supply is adequate for the general population. DRIs represent the intake level of essential nutrients that are judged to be adequate to meet the known nutrient needs of practically all healthy people.
DRIs for protein, energy, vitamins, and minerals have been established — based on scientific knowledge — for infants, children, adolescents, adults, and pregnant and lactating women. DRIs are not adequate to cover special therapeutic needs in patients with chronic diseases, metabolic disorders, and certain infections, and in premature infants.
When should blood levels be measured?
If your routine laboratory tests (including a complete blood count and a chemistry panel) are normal, you do not need a measurement of your blood vitamin or mineral levels. If you are taking a medicine such as a diuretic or water pill, your doctor is most likely already monitoring the level of potassium in your blood.
If you are found to be anemic and your doctor believes it is a result of a nutrient deficiency, your doctor might measure the level of iron in your blood. Iron, in fact, is the only mineral for which blood levels correlate with the total amount of iron stored in your body. Other minerals such as sodium, potassium, phosphorous, calcium, and magnesium are found predominantly in the cells of your body, so blood levels of these nutrients can, at times, be misleading.
If you have a gastrointestinal disease that leads to significant malabsorption, your doctor might measure some of the levels of vitamins and minerals in your blood. Atrophic gastritis, for example, is a condition that specifically leads to the malabsorption of vitamin B12. This vitamin can be measured in your blood if atrophic gastritis is suspected.
When should a vitamin or mineral supplements be taken?
Gastrointestinal diseases can affect levels of vitamins and minerals. Significant malabsorption can result in low levels of all the essential nutrients. However, fat-soluble vitamins, calcium, magnesium, and zinc can be more adversely affected than other nutrients. Cirrhosis of the liver can result in a diminished capacity to store vitamins A and B12. Diseases that result in pancreatic insufficiency and diminished bile acid secretion by the liver can also lead to malabsorption of fat-soluble vitamins.
A well-balanced diet is sufficient to maintain adequate levels of vitamins and minerals for most people. If you have malabsorption or severe liver disease, your doctor can provide oral nutrient supplements. If you have atrophic gastritis, your doctor will likely need to provide you with periodic injections of vitamin B12 to maintain normal body stores.
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This information is provided by the Cleveland Clinic and is not intended to replace the medical advice of your doctor or health care provider. Please consult your health care provider for advice about a specific medical condition. This document was last reviewed on: 12/30/2003
