Scientists reveal the history and benefits of vitamin D read more at here www.spinonews.com/index.php/item/975-scientists-reveal-the-history-and-benefits-of-vitamin-d

When humans are exposed to sunlight, their skin produces vitamin D, a fat-soluble vitamin that offers many health benefits. These benefits include helping maintain a healthy immune system, and the growth and development of bones and teeth.

Sunshine is a marvelous health-giving and healing power in the world. Sit in the sun, recline in the sun, walk on the sunny side of the street, avoid parasols, and ever recognize the sun as a friend and not an enemy, a promoter of health, and a destroyer of disease.

As early as the mid-seventeenth century, two scientists working independently and identified the disease called rickets and observed that it occurred among children who were seldom exposed to sunlight.

This illness was characterized by defective bone growth and horribly deformed bodies. By the twentieth century, it was well established that rickets had something to do with lack of sunlight.

However, Sir Edward Mellanby's studies on dogs helped the substance whose absence caused rickets. His dogs were fed only oatmeal, and they were raised without any exposure to sunlight, which caused them to develop the disease.

He found that the substance was contained in cod liver oil, which he stated with an effective anti-rickets agent; the dogs were cured by adding cod liver oil to their diets.

In the 1930's, the chemical structure of vitamin D was established by German scientists, and they proved that the substance in cod liver oil was vitamin D. 

Vitamin D was established as a prohormone, a substance that is later converted into an active hormone.

Though the interest in vitamin D's power was originally limited to the prevention and treatment of rickets, later it would be found that this substance had myriad other benefits.