Vitamin D3
What is Vitamin D3?
Vitamin D3, also known as cholecalciferol, is one of several Vitamin D compounds known as prohomones. It is produced when the skin is exposed to sunlight.
What is the function of Vitamin D3?
Vitamin D3, along with D2 (known as ergocalciferol) regulates calcium and phosphorous in the blood by controlling their absorption from food in the intestines. Vitamin D3 also contributes to bone growth and immune system function.
What foods provide Vitamin D3?
While Vitamin D3 is synthesized through exposure to sunlight, an increasingly indoor, sedentary lifestyle has increased the need for a diet with Vitamin D-enriched and fortified foods. Good sources of Vitamin D3 include fatty fish (herring, mackerel, salmon, tuna canned in oil and catfish), along with fortified dairy products and cereals.
What is the recommended dose of Vitamin D3?
For men and women over the age of 19, the Recommended Dietary Allowance of Vitamin D (including D3) is 10 micrograms, or 400 International Units per day. Individuals at risk for Vitamin D deficiency may need to consume greater amounts to maintain Vitamin D concentration in the blood.
How does Vitamin D3 deficiency occur?
Vitamin D3 deficiency can occur due to inadequate exposure to sunlight, inadequate dietary intake, poor absorption due to illness, surgery or hereditary condition, or other body characteristics such as the presence of excess body fat or darker skin color.
Vitamin D3 and general Vitamin D deficiency can result in bone deformity and growth issues in children (rickets), osteomalacia (bone thinning) and osteoporosis (bone fragility) in adults.
How much Vitamin D3 is too much? What about drug interactions ?
The body's production of Vitamin D3 is carefully regulated, and most overdose/toxicity situations occur due to use of supplemental Vitamin D. The tolerable upper level intake has been suggested as no more than 250 micrograms (10,000 International Units) per day.
The metabolism of Vitamin D3 (and Vitamin D in general) is impaired by the use of corticosteroid medications, such as prednisone. The absorption of Vitamin D3 (and Vitamin D in general) is reduced by some weight loss and cholesterol-lowering medications.
