Pellagra

<p >Niacin is one of five vitamins (when lacking in human diet) associated with a <a href="http://en.wikipedia.org/wiki/Pandemic" title="Pandemic" >pandemic</a>&nbsp;

<a href="http://en.wikipedia.org/wiki/Nutrition_disorder" title="Nutrition disorder" >deficiency disease</a>:&nbsp;

niacin deficiency (<a href="http://en.wikipedia.org/wiki/Pellagra" title="Pellagra" >pellagra</a>),&nbsp;

<a href="http://en.wikipedia.org/wiki/Vitamin_C" title="Vitamin C" >vitamin C</a> deficiency (<a href="http://en.wikipedia.org/wiki/Scurvy" title="Scurvy" >scurvy</a>),

&nbsp;<a href="http://en.wikipedia.org/wiki/Thiamin" title="Thiamin" class="mw-redirect" >thiamin</a>&nbsp;deficiency (<a href="http://en.wikipedia.org/wiki/Beriberi" title="Beriberi" >beriberi</a>),&nbsp;

<a href="http://en.wikipedia.org/wiki/Vitamin_D" title="Vitamin D" >vitamin D</a>&nbsp;deficiency (<a href="http://en.wikipedia.org/wiki/Rickets" title="Rickets" >rickets</a>),&nbsp;

<a href="http://en.wikipedia.org/wiki/Vitamin_A_deficiency" title="Vitamin A deficiency" >vitamin A deficiency</a>&nbsp;(<a href="http://en.wikipedia.org/wiki/Night_blindness" title="Night blindness" class="mw-redirect" >night blindness</a>&nbsp;and other symptoms).&nbsp;</p>