Day 140: Vitamin D

Vitamin D is one of the more interesting vitamins needed by the human body.  Unlike other nutrients that must be digested vitamin D can be synthesized by the human body when exposed to ultra violet light.  To sum it up in 1925 a scientist named Alfred Fabian Hess simply stated “light equals vitamin D.”

In the 1920s the scientific community was searching for ways to cure rickets.  A biochemist named Harry Steenbock demonstrated that UV light increased the content of vitamin D in food.  He fed this food to rodents with rickets and it cured them.  By 1945 rickets had all but been eliminated in the US.

According to the Mayo Clinic the major function of vitamin D on a biological level is to maintain normal blood levels of calcium and phosphorus.  Vitamin D is a major building block used to increase bone density.  Research also suggests that Vitamin D may help high blood pressure, cancer, and other autoimmune diseases.

There are few foods that contain vitamin D, they include: Fatty fish (tuna, salmon, mackerel, etc.) beef liver, cheese, and egg yolks.  It has also been found that some mushrooms synthesize vitamin D contain variable amounts of vitamin D as well.

The best source of Vitamin D is sunlight.  Interestingly cloud cover reduces the bodies ability to produce vitamin D by 50% and if your in the shade it reduces farther to 60%.  The type of UV light a body needs does not penetrate glass so exposure to sunlight indoors does not produce any vitamin D. 

The amount the body needs varies from male to female and with age.  I found some research that suggest a little as 400 IU for adults to 2000 IU.  Most of our food has now been fortified with vitamin D as well. 

Daily recap:

Matt and Kelly: 30 Minute jog.