B vitamins
<p >The B vitamins are necessary to:</p>
<ul >
<li >Support and increase the rate of <a href="http://en.wikipedia.org/wiki/Metabolism" title="Metabolism" >metabolism</a><sup id="cite_ref-0" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitamin_B_complex#cite_note-0" >[1]</a></sup></li>
</ul>
<p > </p>
<ul >
<li >Maintain healthy skin, hair and <a href="http://en.wikipedia.org/wiki/Muscle_tone" title="Muscle tone" >muscle tone</a><sup id="cite_ref-1" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitamin_B_complex#cite_note-1" >[2]</a></sup><sup id="cite_ref-2" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitamin_B_complex#cite_note-2" >[3]</a></sup></li>
</ul>
<p > </p>
<ul >
<li >Enhance <a href="http://en.wikipedia.org/wiki/Immune_system" title="Immune system" >immune</a> and <a href="http://en.wikipedia.org/wiki/Nervous_system" title="Nervous system" >nervous system</a> function<sup id="cite_ref-3" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitamin_B_complex#cite_note-3" >[4]</a></sup><sup id="cite_ref-4" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitamin_B_complex#cite_note-4" >[5]</a></sup></li>
</ul>
<p > </p>
<ul >
<li >Promote <a href="http://en.wikipedia.org/wiki/Cell_growth" title="Cell growth" >cell growth</a> and <a href="http://en.wikipedia.org/wiki/Cell_division" title="Cell division" >division</a>, including that of the <a href="http://en.wikipedia.org/wiki/Red_blood_cell" title="Red blood cell" >red blood cells</a> that help prevent <a href="http://en.wikipedia.org/wiki/Anemia" title="Anemia" >anemia</a></li>
</ul>
<p > </p>
<ul >
<li >Reduce the risk of <a href="http://en.wikipedia.org/wiki/Pancreatic_cancer" title="Pancreatic cancer" >pancreatic cancer</a> - one of the most lethal forms of cancer<sup id="cite_ref-5" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitamin_B_complex#cite_note-5" >[6]</a></sup> - when consumed in food, but not when ingested in vitamin tablet form.<sup id="cite_ref-6" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitamin_B_complex#cite_note-6" >[7]</a></sup><sup id="cite_ref-7" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitamin_B_complex#cite_note-7" >[8]</a></sup></li>
</ul>
<p >
All B vitamins are water-soluble, and are dispersed throughout the body. </p>
<p>
Most of the B vitamins must be replenished regularly, since any excess is excreted in the <a href="http://en.wikipedia.org/wiki/Urine" title="Urine" >urine</a>.<sup id="cite_ref-8" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitamin_B_complex#cite_note-8" >[9]</a></sup> This can result in the urine produced being a bright green-yellow colour.</p>
<p>
B vitamins have also been hypothesized to reduce the symptoms of <a href="http://en.wikipedia.org/wiki/Attention_deficit_hyperactivity_disorder" title="Attention deficit hyperactivity disorder" >attention deficit hyperactivity disorder</a>.<sup id="cite_ref-9" class="reference" ><a href="http://en.wikipedia.org/wiki/Vitamin_B_complex#cite_note-9" >[10]</a></sup></p>