Vitamin D is a fat-soluble vitamin that helps the body absorb calcium. Fat-soluble vitamins are stored in the body's fatty tissue.

In addition to helping the body absorb calcium, vitamin D also helps the body keep the right amount of calcium and phosphorus in the blood.

Vitamin D is found in the following foods:

• Dairy products
  • Cheese
  • Butter
  • Cream
  • Fortified milk (all milk in the U.S. is fortified with vitamin D)
• Fish
• Oysters
• Fortified cereals
• Margarine

Vitamin D deficiency can lead to osteoporosis in adults or rickets in children.

Too much vitamin D can make the intestines absorb too much calcium. This may cause high levels of calcium in the blood. High blood calcium can lead to calcium deposits in soft tissues such as the heart and lungs. This can reduce their ability to function.

Kidney stones, vomiting, and muscle weakness may also occur if you have too much vitamin D.

The best way to get the daily requirement of essential vitamins is to eat a balanced diet that contains a variety of foods from the food guide pyramid.

Vitamin D is also known as the "sunshine vitamin" because the body manufactures the vitamin after being exposed to sunshine. Ten to 15 minutes of sunshine 3 times weekly is enough to produce the body's requirement of vitamin D.

Specific recommendations for each vitamin depend on age, gender, and other factors (such as pregnancy). In general, those over age 50 need slightly higher amounts of vitamin D than younger persons.