The B Vitamins Complex Benefits and Dosage
The B vitamins formerly were thought to be a single vitamin, but further research showed that they are distinct vitamins that often coexist in the same foods. Generally the term B vitamins refers to the eight different types of vitamin B that, taken together, are called the vitamin B complex.
The B vitamins work together and are interdependent. Some B vitamins require other B vitamins for synthesis or activation. Together the vitamin B complex is needed to promote cell growth and division and maintain metabolism and muscle tone, as well as healthy skin, hair, and eyes.
B1 (Thiamine) plays an important role in helping the body metabolize carbohydrates to produce energy. It is essential to normal growth and development and helps maintain the proper functioning of the heart and the nervous and digestive systems. Foods naturally high in thiamine include spinach, peas, liver, beef, pork, legumes, bananas, and whole grains. The RDA for women is 1.1 mg; for men, 1.2 mg.
B2 (Riboflavin) is used in a wide variety of cellular processes and helps metabolize fats, carbohydrates, and proteins. Foods naturally high in riboflavin include milk, cheese, meat, liver, fish, yogurt, eggs, soybeans, and bananas. Exposure to light destroys riboflavin. The RDA for women is 1.1 mg; for men, 1.3 mg.
B3 (Niacin) is needed for energy production in cells and helps with DNA repair. It also helps remove toxins from the body. Supplemental niacin can cause facial flushing. Foods naturally high in niacin include organ meats, chicken, salmon, tuna, nuts, legumes, and many fruits and vegetables. The RDA for women is 14 mg per day; for men, 16 mg.
B5 (Pantothenic acid) is critical to the metabolism of carbohydrates, fats, and proteins. Foods naturally high in pantothenic acid include eggs, whole grain cereals, legumes, and meat, although it is found in some quantity in nearly every food. The Adequate Intake (AI) for women and men is 5 mg.
B6 (Pyridoxine) plays a role in the functioning of over 100 enzymes, including those that synthesize neurotransmitters. It helps the body metabolize proteins and carbohydrates and helps maintain red blood cells. Pyridoxine plays a role in the all-important balancing of sodium and potassium (potassium is discussed more fully earlier in this chapter). Foods naturally high in pyridoxine include salmon, chicken, turkey, bananas, spinach, and potatoes. The RDA for women and men up to age 50 is 1.3 mg; for women 51 and up, 1.5 mg; for men 51 and up, 1.7 mg.
B7 (Biotin) is sometimes called "the beauty vitamin" because it is important for healthy skin and hair. Biotin helps produce energy during aerobic respiration, helps synthesize fatty acids, and plays a role in metabolizing protein. Usually the "friendly" bacteria in the intestinal tract make enough biotin to meet the body's needs. The Adequate Intake (AI) for women and men is 30 micrograms.
B9 (Folate) plays an important role in many body processes. Folate is widely available; rich sources include leafy vegetables, dried legumes, fruits and vegetables, whole grains, meat and poultry. Folic acid is the synthetic form of the vitamin that is used in supplements and fortified foods. Folate helps with many jobs in the body, including cell maintenance and repair, DNA synthesis, and the formation of red and white blood cells. The RDA for women and men is 400 micrograms, but women who are pregnant or planning to become pregnant should consume 600 micrograms a day because folic acid protects against neural tube defects in the baby.
B12 (Cobalamins) plays a role in growth and development, helps brain function, and contributes to the formation of red blood cells. It is involved in the metabolism of every cell of the body, affecting not only DNA synthesis but also the synthesis of fatty acids and energy production. B12 can be found naturally only in animal sources, such as clams, salmon, oysters, beef, chicken, turkey, milk, and cheese. The RDA for women and men is 2.4 micrograms.