how much sunlight is need to produce vitamin d
In the final stage of the process, the liver and kidneys convert that vitamin D into yet another form of the vitamin -- vitamin D3, the active form of the vitamin that our bodies can use. You need just 10 to 20 minutes of sunlight a day to ensure that your body is producing enough vitamin D. After we reach our seventies, the precursor to vitamin D generally found in skin diminishes three- or four-fold, making it increasingly difficult for us to produce vitamin D naturally.
A Dr. Mehmet Oz, MD , Cardiology (Cardiovascular Disease), answered. Most people get their vitamin D by exposing their bodies to the sun's rays. It typically takes at most 30 minutes of exposure twice a week to synthesize all of the vitamin D you need. You should keep in mind, however, that staying in the sun for too long could cause skin damage and put you at greater risk for developing a skin disorder or disease.