Vitamins are the essential ingredients for the chemical reactions that sustain life. These nutrients perform various functions in the body, from metabolism to red blood cell formation and other essential processes. The recommended daily allowance for most vitamins is measured in micrograms or milligrams. A single multivitamin pill taken daily can contain all of required vitamins your body needs.
How Much Is a Milligram?
If you can visualize it, you will get a better understanding of the required amounts for different vitamins. A teaspoon contains 5 mL. If you assume 1 mL equals 1 g, then 5 mL equals 5 g or 5,000 mg. As an example, the RDA for vitamin C is 75 mg per day for adult women, according to the Linus Pauling Institute. Thus, the amount of vitamin C you need daily is quite small.
One of the reasons you only need vitamins in small quantities is that chemical reactions occur at the molecular level. This means that reactions do not require a specified amount of a vitamin like a recipe; rather, the need is measured in the number of molecules. The chemical structure of a vitamin may contain hundreds of molecules, each able to participate in reactions with other chemicals present in the body.
Vitamins are chemical substances, just like other medications or supplements you may take. Even though they provide health benefits, there is an optimal range of intake for most vitamins. Some vitamins, such as vitamin A, are toxic at high doses. Excessive vitamin A intake can lead to weight loss, fatigue and even liver damage, warns Whole Health MD. Likewise, high intake of folic acid can hide the neurological damage of a vitamin B12 deficiency.
You can group vitamins into two basic groups: water soluble and fat soluble. Water-soluble vitamins dissolve readily in water. They include the B vitamins and vitamin C. The body does not store large quantities of these vitamins, making meeting RDAs more important. Fat-soluble vitamins include vitamins A, D, E and K, which dissolve in fat. This characteristic means that these vitamins are stored in the body. Excessive intake is possible because the body may not deplete its stored supply every day.
You can get adequate amounts of vitamins through a healthy, varied diet that includes plenty of fresh fruits and vegetables and lean sources of protein. Adjusting dietary intake is preferable to taking supplements because of the other nutrients you receive when you eat a balanced diet. Your body's need for vitamins will change during your life. You may need higher amounts of certain vitamins during pregnancy, for example. Your body's ability to absorb vitamins may diminish as you age, requiring supplementation. For optimal health, do not exceed the RDAs for vitamins. The small amounts mean that there can be a risk of overdosing.