Chapter 18.1b Nutrition

Vitamins Vitamins are organic nutrients that are needed in small quantities for growth, regulating body functions, and preventing some diseases. Bone cells need vitamin D to use calcium, and your blood need vitamin K to clot. Many food supply some vitamins but not all vitamins.

There are 2 groups of vitamins – some vitamins dissolve easily and are called water soluble vitamins. They are not stored in your body so you need them every day. Other vitamins dissolve only in fat and are called fat-soluble vitamins. These vitamins will be stored in your body. Your body makes some vitamins – Vitamin D is made when your skin is exposed to sunlight. Vitamin K and 2 vitamin Bs are made with the help of bacteria that live in the large intestine.

Minerals Minerals are inorganic nutrients that regulate chemical reactions in your body. Your body needs about 14 different minerals. Minerals build cells, take part in chemical reactions in cells, send nerve impulses throughout your body, and carry oxygen to body cells. Calcium and phosphorous are used in the largest amounts. Others are only needed in small amounts.

Water Your cells need water to do their jobs. Most of the nutrients we learned about need water to dissolve them. In cells chemical reactions must have water to take place. The human body is about 60% water. 2/3 of that water is in cells and body fluids like blood. You lose water by sweat and when you exhale water vapor comes out. You also lose water when you get rid of wastes. You need about 2L of water everyday. Many food you eat also supply your body with water.

Why do you get thirsty? When your body needs water, messages are sent to your brain and that makes you feel thirsty. Drinking water satisfies the thirst and restores homeostasis – your body’s internal environment. When this happens you no longer feel thirsty.

Food Groups You need to eat a variety of foods because no food has every nutrient you need. One way to do that is the food pyramid. It uses food groups – foods that contain the same type of nutrient. There are 5 food groups – bread and cereal, vegetable, fruit, milk, and meat.

Daily Servings Each day you should eat 6 to 11 servings from the bread and cereal group, 3-5 servings from the veggie group, 2-4 from the fruit group, 2- 3 servings from the milk group, and 2-3 servings from the meat group. Small amounts of fats, oils, and sweets should be eaten. Serving sizes are different for different foods.

Food Labels Nutritional facts let you know what is found on packaged food to help you make healthy choices.