The Importance of Vitamins Reading Answers

As a fat-soluble vitamin, vitamin D in excess is not flushed from your body through urine. Although your body can become toxic from excessive supplemental intake, the toxicity does not derive from vitamin D-rich foods or sun exposure. The maximum amount of vitamin D that adults can safely obtain from supplements is 4,000 international units (IU) per day. If you exceed this limit, the excess vitamin D stays in your blood causing adverse effects such as unintentional weight loss, anorexia and abnormal heart rhythms. Excess vitamin D can raise your blood levels of calcium, causing heart, blood vessels and kidney damage. Consuming smaller amounts- for example, 1,000 lU per day - along with calcium in supplement form increases your risk for kidney stones. Sufficient intake of vitamin D for most adults is 600 IU daily from food or supplements.

Vitamin D is present in your body tissues and blood. Although you obtain vitamin D from foods, your body also produces it in response to sun exposure. Vitamin D in your bloodstream appears in blood tests and has a relatively long circulating life of about 30 days. In other words, if you consume vitamin D-rich foods or supplements today, a portion will likely stay present in your body for one month. The length of time vitamin D remains in your body tissues remains unclear, however.

Foods, dietary supplements and sun exposure provide vitamin D. Getting sufficient amounts is vital for overall health. Your skeletal system requires vitamin D because the vitamin facilitates calcium absorption, a key for healthy bones and development. Your liver, not your bones, produces vitamin D in response to the sun's ultraviolet rays. Valuable food sources of this vitamin include cod liver oil, seafood such as salmon and tuna, and fortified juices and dairy products. Eggs, margarine and fortified cereals contain moderate amounts.

Like the rest of your body, your digestive system requires all essential vitamins and minerals. B vitamins and vitamin C, however, play particularly valuable roles in digestive health, says Dr. Chris Iliades, a physician and contributing health writer for EveryDayHealth.com. The B vitamin folate, or folic acid, is linked with a reduced risk for colon cancer. Vitamin B1, also called thiamine, helps your body convert carbohydrates into energy during digestion. Vitamin B3, or niacin, allows for normal breakdown of carbohydrates, fats and alcohol. Vitamin B6, or pyridoxine, promotes protein digestion. 

Vitamin B12 greatly benefits your central nervous system. The antioxidant- vitamin C enhances iron absorption and gum and tooth health. To meet your B vitamin needs, Illiades suggests eating a diet rich in whole grains, beans, seafood, dairy products and leafy green vegetables. To obtain vitamin C, you should consume a variety of fruits and vegetables Top vitamin C sources include citrus fruits, tomatoes, strawberries, bell peppers and sweet potatoes