The major biologic function of vitamin D is to maintain normal blood levels of calcium and phosphorus. Vitamin D aids in the absorption of calcium, helping to form and maintain strong bones.
Research suggests vitamin D may provide protection from osteoporosis, hypertension (high blood pressure), cancer, and several autoimmune diseases.
Vitamin D is found in many dietary sources such as fish, eggs, fortified milk, and cod liver oil.
Sun Exposure and Vitamin D
Vitamin D is also known as the "sunshine vitamin" because the body manufactures the vitamin after being exposed to sunshine.
Being in sunshine for 10–15 minutes, 3 times a week, is enough to produce the body’s requirement of vitamin D.
Foods Rich in Vitamin D
Vitamin D is found in the following foods:
- cheese, butter, and cream
- fortified milk (all milk in the U.S. is fortified with vitamin D except for organic products)
- fish and oysters
- fortified cereals