The water-soluble vitamin group consists of the B-complex vitamins and vitamin C. Water-soluble vitamins dissolve in water and are then carried in your bloodstream. Most are not stored in the body in any significant amounts. What your body does not use is excreted through the urine. Since they are not stored in the body, water-soluble vitamins pose less of a risk for toxicity (though moderation is still the best approach). This also means that you need a regular supply from your diet.

Folic Acid

Folic acid is a B vitamin whose main role is to maintain the cell's genetic code or DNA (the cell's master plan for cell reproduction). It also works with vitamin B12 to form hemoglobin in red blood cells. Folic acid has gained much attention for its role in reducing the risk for neural tube birth defects, such as spina bifida, in newborn babies. Other risks of folic acid deficiencies include anemia, impaired growth, and abnormal digestive function. It is vital that pregnant women or women of childbearing years consume enough folic acid through food and supplements, especially during the first trimester.

Before pregnancy a woman's need for folic acid is 400 mcg per day. During pregnancy, that amount jumps to 600 mcg per day. Recent studies show that to decrease the risk of birth defects, women planning a pregnancy should increase their daily intake of folic acid to 800 to 1,000 mcg. Most prenatal vitamins contain 800 to 1,000 mcg to ensure that women fully absorb the amount they need during pregnancy to help decrease the risk of birth defects. Taking too much folic acid through supplements can mask a vitamin B12 deficiency and could interfere with some medications. However, some women may need more folic acid with certain medications.

Other B Vitamins

Vitamin B6 is necessary in helping your body make nonessential amino acids (the building blocks of protein). These nonessential amino acids are used to make necessary body cells. Vitamin B6 also helps to turn the amino acid tryptophan into niacin and serotonin (a messenger in the brain). In addition to those functions, this vitamin helps produce insulin, hemoglobin, and antibodies that help fight infection. Requirements are increased slightly in pregnancy due to the needs of the baby. The recommended level during pregnancy is 1.9 mg.

Requirements are also increased for vitamin B12 during pregnancy to help with the formation of red blood cells. The increase is slight, from 2.4 mcg before pregnancy to 2.6 mcg during pregnancy. This vitamin is found mostly in foods of animal origin, so vegetarians need a reliable source of vitamin B12, such as fortified breakfast cereal or supplements.

Vitamin C

Vitamin C produces collagen, a connective tissue that holds muscles, bones, and other tissues together. In addition it helps with a variety of other functions, including forming and repairing red blood cells, bones, and other tissue; protecting you from bruising by keeping capillary walls and blood vessels firm; keeping your gums healthy; healing cuts and wounds; and keeping your immune system strong and healthy. Vitamin C also helps your body absorb iron from plant sources, which is not as easily absorbed as iron from animals. Vitamin C is one of the very powerful antioxidants that attacks free radicals (unstable molecules with a missing electron formed when the body's cells burn oxygen) in the body's fluids. These free radicals can damage the body's cells, tissues, and even DNA (your body's master plan for reproducing cells).

With pregnancy, a woman's need for vitamin C increases slightly, from 75 mg to 85 mg (for women nineteen to fifty years). Because vitamin C is so readily available in numerous food sources, it is not difficult to get the extra you need.