Vitamin D3, also called cholecalciferol, is the form of vitamin D the body naturally makes from sunlight. Vitamin D2, also called ergocalciferol, is sometimes used in supplements. Most experts recommend taking vitamin D3 rather than D2 because it is the form that is naturally made by the body. Vitamin D3 may also be easier to absorb. The final benefit of vitamin D3, compared to vitamin D2, is the body limits the amount of D3 that can circulate in the blood, so the risk of taking too much is lower. Vitamin D is a fat soluble vitamin and should be take with your fattest meal of the day for better absorption.
Vitamin D3 is good for achieving an optimal level of vitamin D in the blood. The National Institutes of Health Office of Dietary Supplements says vitamin D is necessary for calcium and phosphorus absorption, immune function, nervous system activity, cell formation and muscle function. Although vitamin D is found in some foods, it is not found in great enough quantities to satisfy the body’s minimum requirements. The only ways to get the amount of vitamin D necessary are to take supplements or spend time in the sun, according to the Vitamin D Council. When the skin is exposed to sunlight, it produces vitamin D. How much vitamin D is produced depends on the amount of skin exposed, the time of day, the color of the person’s skin and the location. The lighter someone’s skin, the easier it is for that person to produce vitamin D. Due to sunblock, and limited exposure to the sun ,preventing skin cancer it is advisable to supplement with Vit D3. The Vitamin D Council recommends taking vitamin D3 supplements rather than D2 supplements when possible. D3 is the type of vitamin D produced when the skin is exposed to the sun.
Vitamin D3 can interact with some medications, It is always best to consult your doctor if you have any questions regarding interactions or the pharmaceutical company directly.