Section 13-1 Nutrients at Work for You 329 Copyright Goodheart-Willcox Co., Inc. B Vitamins The B vitamins are a group of similar vitamins, but each plays its own role in helping the body function properly. Thiamin, ribofl avin, and niacin may be the most well-known B vitamins. They help you obtain energy from the foods you eat. Folic acid and vitamin B 12 are also members of this vitamin group. See 13-4. Good sources of thiamin include whole-grain and enriched grain products. (Enriched means nutrients that were lost during processing have been added back to a product.) A defi ciency of thiamin can result in nausea, depression, loss of appetite, and fatigue. A severe defi ciency can lead to a disease called beriberi. This disease causes numbness in the ankles and legs and leads to paralysis and heart failure. Ribofl avin and niacin play an important role in the health of your skin and digestive system. A defi ciency of ribofl avin can cause cracked lips, a skin rash, and extremely sensitive eyes. A defi ciency of niacin can cause pellagra, which affects the skin and digestive system. The body uses folic acid to make all new cells. All women of childbearing age are urged to be sure they are meeting their folic acid needs. The spine and brain of a baby growing in its mother’s womb may not develop properly if the mother’s diet lacks folic acid. Vitamin B 12 naturally occurs only in foods of animal origin. People who do not eat these foods may obtain the vitamin from supplements or fortifi ed soy milk. A vitamin B 12 defi ciency can result in anemia and nerve damage. Vitamin C To prevent a defi ciency of vitamin C, be sure to eat at least one serving of a food high in this vitamin each day. A lack of vitamin C over time may result in bleeding gums, loose teeth, bruising, and sore joints. A severe defi ciency of vitamin C can lead to a disease called scurvy. Water Perhaps you do not think of water as a nutrient, but it is one of the most important nutrients. Over half the body’s weight is water. A general recommendation is to drink nine to twelve cups of water each day, although most people can let thirst determine their intake. You get additional water from the foods you eat. Water is also a product of chemical reactions that take place in your body. 13-4 Breads made with enriched or whole-grain flour are good sources of the B-vitamins thiamin, riboflavin, niacin, and folic acid. Living Living Green Green Drinking bottled water may be convenient, but it takes a lot of resources to produce. Many empty plastic bottles end up in the trash. Save money and help the environment by filling up your own reusable drinking bottle instead.