Vitamin D and Sunshine

by Bob Gariano

At this time of year, days get shorter and the dark nights get longer in the northern hemisphere. During the winter months, the human body has less access to natural sunlight and the positive effects of irradiation caused by the sun’s ultraviolet light striking the cells of the skin. We know today that exposure to natural sunshine is important as our bodies manufacture certain essential substances and stay healthy.

Rickets in Children

The metabolic effect of sunshine on human cells provides a foundation for one of the most impressive medical detective stories. For centuries, many people had been afflicted with a debilitating disease called rickets. This crippling and usually fatal disease was characterized by bow legs, knock knees, spinal atrophy, convulsions, and breathing problems. Sadly, the disease was particularly prevalent in children.

Ancient Roman and Chinese doctors wrote of this malady, which was widespread especially among poorer people with limited diets. Rickets became even more prevalent during the 1800s as people moved from their farms to take up industrial jobs in cities. Physicians speculated that the foul air and poor hygienic conditions of the newly expanding cities in industrial economies were to blame. They tried treating rickets with the best tools they had at hand including braces for limbs and blood letting. In spite of their efforts, rickets remained a tragic and all too common childhood affliction.

Sunshine Connection

In 1892 a British medical researcher, T. A. Palm, published a paper demonstrating an unexplained connection between the incidence of rickets and the amount of sunshine in a particular region. The relationship was simply that more sun correlated with less incidence of rickets. Building on that idea, in 1913, researchers at the University of Wisconsin induced rickets in goats by keeping them indoors and away from natural sunshine for long periods.

In 1918, a British researcher, Edward Mellanby, studying the dietary influences of rickets in dogs, found that he could create the symptoms of the disease by feeding them porridge and keeping them indoors. Without exposing them to sunlight, he found that these effects could be reversed by giving them a daily issue of cod liver oil. He decided that it was the recently discovered vitamin A in the oil that cured rickets.

Hearing of this nutritional research, Dr. McCollum at the University of Wisconsin conducted similar tests, but used cod liver oil which had been heated to destroy the vitamin A. The remedy still worked and this led him to identify a new vitamin in the oil as the real remedy. He named it vitamin D.

Public health officials now had two distinct remedies for rickets. The patients could be cured either with regular exposure to the ultraviolet radiation in sunlight or through daily doses of cod liver oil. Unfortunately, neither of these remedies was readily accepted by people who were living in cities and working indoors long hours for the first time in history. Another answer had to be found if a general remedy to rickets could be introduced.

Irradiation and Hormones

Over the next five years, vitamin D became a subject of intense medical scrutiny and chemical research. What was thought originally to be a vitamin is actually a hormone precursor that is found in many animal and plant tissues. It was discovered that this substance is produced by a variety of living cells when they are exposed to the sun’s ultraviolet radiation. Researchers began irradiating various organic materials including milk, lettuce, animal tissues, and eggs. They found that all of these tissues produced similar hormones that could drive the production of vitamin D in the human body.

The introduction of such outside radiant energy induces the skin of animals and humans to produce the vitamin precursor. This chemical then undergoes a series of transformations in the liver, eventually reaching receptors in various tissues including the bones, heart, kidney, and other organs. Today we know that the hormone, known as vitamin D, has a role in combating a variety of diseases including rickets, certain cancers, diabetes, and infections.

Researchers at the University of Wisconsin finally recognized that childhood rickets could be largely eliminated simply by irradiating certain common foods with ultraviolet light. In 1924 Dr. Steenbock, at Wisconsin, patented the food irradiation process using ultraviolet light. All future financial proceeds from the patent were donated to be used for further nutritional research at the university.

Food Additives

In 1936, Adolf Windaus, a leading organic chemist, was invited to the US from his native Germany, to study cholesterol and other little known organic substances. As a part of this research, Windaus discovered a large scale process to manufacture synthetic vitamin D which could economically be used in foods.

Not only was this process more economical than irradiation, but it does not alter food flavors as irradiation sometimes does. Today, vitamin D enriched foods have all but eradicated rickets among children. Based on his work on the organic chemistry of sterol and vitamins, Dr. Windaus received the Nobel Prize for chemistry.

Eradicating Disease

Today we know that vitamin D is not a vitamin at all. Vitamins are essential substances that the body requires but which it cannot make. Vitamins must be consumed from sources outside the body. Vitamin D is actually a hormone manufactured in our bodies. It is closely related to steroid hormones. The precursor substance is manufactured by the tissues in our skin when those tissues exposed to the ultraviolet radiation of the sun and then it is converted to useful form in the liver and kidneys.

We have come to accept that fortified foods have all but eliminated certain diseases like rickets, scurvy, and beriberi. Research into vitamin D and the work of scientists to understand this critical chemical was the basis for these improvements in our quality of life. We may miss the warm sun of spring and summer during this time of year, but at least the scourge of rickets and other diseases caused by vitamin D deficiencies are a thing of the distant past.

Bob Gariano is President of RGA, an executive search firm that recruits senior executives and board members for public and private companies. Bob can be reached at [email protected]