Health Illustrated Encyclopedia

Vitamin D

Definition

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

Function

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.

Food Sources

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

Side Effects

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.

Recommendations

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.


Provided by adam.com

Review Date: 1/2/2007
Reviewed By: William McGee, MD, MHA, Assistant Professor of Medicine and Surgery, Tufts University School of Medicine, Boston, MA, and Chairman, Nutrition Committee, Baystate Medical Center, Springfield, MA. Review provided by VeriMed Healthcare Network.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.