Reel Doctor Talk

Even the blind need sunlight

by Smitha R. Chadaga

In Netflix's new series, The OA, when Prairie Johnson (Brit Marling, @britmarling) returns home after having been missing for seven years, questions abound regarding her time away - where was she? was she abused? did it really happen? Prairie at one point questions her experience and her FBI liaison (Riz Ahmed@rizmc) stops her and offers proof of her time away.  One objective example he gives is the vitamin D deficiency she had on return.  But how does lack of sunlight cause vitamin D deficiency?


The natural way the body gets vitamin D is by making it.  A cholesterol is present in the skin and when UVB rays of sunlight hits this cholesterol it turns into vitamin D3.  Vitamin D is also found in certain natural foods (fish and eggs) and other fortified foods (dairy and grains).


Of course if some one was held captive for seven years it would make sense that they get vitamin D deficiency.  But it takes less than you might think to acquire Vitamin D deficiency.  You are at risk of vitamin D deficiency if you

1.  lack regular exposure to sunlight - such as if you are home bound, are restricted to a care facility or live at northern latitudes

2.  follow a strict diet - such as a vegan diet

3.  have darker pigment skin - because the skin pigment interferes with the conversion of cholesterols to vitamin D

4.  have intestinal disorders (including Crohn's disease and ulcerative colitis) that cause problems absorbing fat - vitamin D is a fat soluble vitamin

5. are an older individual - as you get older the skin has a harder time converting cholesterols to vitamin D


It doesn't take that much sunlight to get vitamin D.  For most people walking around with arms and hands exposed in the warmer months will produce adequate amounts of vitamin D.  Being outdoors is key as windows block out the UVB that is needed to convert cholesterols in the skin to vitamin D. 


So as winter and the holidays descend upon us try to take a stroll outside - in the sun.