Factors that Affect Function deficiency of vitamin D

What factors might contribute to a deficiency of vitamin D?

Insufficient sun exposure

By far the most important D-deficiency contributing factor faced worldwide is insufficient exposure to sunlight. More specifically, it is ultraviolet B sunlight in the range of 290-300nm that is needed to convert 7-dehydrocholesterol found in our skin cells into cholecalciferol (the preliminary form of vitamin D3).

Drug-Nutrient Interactions

What medications affect vitamin D?

The following medications impact the absorption, utilization, and/or activation of vitamin D:

• Anticonvulsant medications, including Dilantin, are used to control seizure activity in people with epilepsy and brain cancer, and those who have suffered head trauma through injury or stroke. These medications decrease the activity of vitamin D.
• Bile acid sequestrants (Cholestyramine, Colestipol) are a class of drugs used to lower cholesterol levels. These drugs may reduce the intestinal absorption of the fat-soluble nutrients, including vitamins A, D, E, and K.
• Cimetidine (Tagamet and Tagamet HB) prevents the release of hydrochloric acid into the stomach and is used to treat the symptoms associated with stomach and duodenal ulcers and acid reflux. This drug may reduce vitamin D activation by the liver.

Nutrient Interactions

How do other nutrients interact with vitamin D?

Vitamin D plays a role in maintaining normal blood levels of calcium. As a result, vitamin D impacts the absorption and storage of calcium. Vitamin D also stimulates the absorption of phosphorus.

Vitamin D helps to regulate the production of certain calcium-binding proteins that function in the bones and kidneys. Because these binding proteins are also dependent on vitamin K, interrelationships between vitamin D and vitamin K have become the subject of active research investigation.

Health Conditions

What health conditions require special emphasis on vitamin D?

Vitamin D may play a role in the prevention and/or treatment of the following health conditions:

• Asthma (severe childhood)
• Atherosclerosis
• Bladder cancer
• Breast cancer
• Chronic fatigue syndrome

Food Sources vitamin

What foods provide vitamin D?

Excellent sources of vitamin D include salmon and sardines while very good sources include vitamin-D fortified milk.

Good food sources of vitamin D include goat's milk, shiitake mushrooms, and eggs.

Introduction to Nutrient Rating System Chart

In order to better help you identify foods that feature a high concentration of nutrients for the calories they contain, we created a Food Rating System. This system allows us to highlight the foods that are especially rich in particular nutrients.

Public Health Recommendations

In 2010, the Institute of Medicine at the National Academy of Sciences established revised Dietary Reference Intake (DRI) recommendations for vitamin D based on new research in this area. The following Adequate Intake (AI) levels for vitamin D were established in 2010 for infants:

• Infants 0-6 months: 10 micrograms (400 IU) per day
• Infants 6-12 months: 10 micrograms (400 IU) per day

The following Recommended Dietary Allowances (RDAs) were established for children, teenagers, and adults: