The D vitamin is the only vitamin that is not obtained from foods that are consumed. Instead, the D vitamin is actually obtained by sunlight on the skin. There has been a lot of media coverage about the dangers of getting too much sun but it is essential that the skin is exposed to sunlight to obtain the recommended daily allowance of the D vitamin. In reality, the amount of time that a person has to spend in the sun to receive a sufficient dose of the D vitamin is extremely small and just a few minutes a day will be sufficient and not have any adverse effects from the amount of ultra-violet light received.
The most important function of the D vitamin is to help control how much calcium is absorbed from food. The majority of the calcium is used to build strong teeth and bones but it is also needed to send messages along the nerves and to help muscles, such as the heart muscles, to contract. It is the D vitamin that ensures that there is always sufficient calcium in the blood to perform these tasks. Other functions that require the D vitamin relate to the immune system and it is believed that it is also a contributing factor in reducing the risk of contracting cancer and,...