Monthly Archives: July 2011

ARE NICOTINAMIDE AND NICOTINIC ACID-NIACIN IDENTICAL?

neil.burman@gmail.com

a pharmacist asks: surely niacin and nicotinamide are the same?

But they are not, although they are both vitamin B3. But nicotinamide has an amide NH moiety  substituted for one oxygen molecule in nicotinic acid, hence nicotinamide is an antioxidant, nicotinic acid is not.

in the food chain, both occur in balance. Niacin metabolizes to nicotinamide and NAD. It doesnt work the other way round, so nicotinamide has no benefit on lipidemia.
 
as supplements the two different forms of vit B3 have major different effects. In a multisupplement we put both in ~ RDA dose.
But for pharmacological benefits we use up to 100 fold  higher doses eg over a gm of niacin for lipidemia or a few hundred mg of nicotamide as part of an antiinflammatory or antidiabetic combo.

This table (derived from Wikipedia, from Pubmed and from the Linus Pauling Institute website of Oregon State university) summarizes the biochemical and clinical differences:

EFFECTS OF THERAPEUTIC DOSES WELL BELOW 3GM/D

property NICOTINIC ACID NICOTINAMIDE
     
formula C6H5NO2 acid C6H6N2O amide
molecular wt 123.1 122.1
lipids-          LDL, Lp(a), Tg, fall significantly no effect
          HDL rises significantly no effect
Anti-inflammatory   yes -anti-acne, skin whitener, antiosteoarthritic.
psychiatric  antidepressant anxiolytic
sirtuins   activates        (anti-Alzheimers)
vasodilator yes no
coronary artery disease reduced. reduced
deficiency pellagra only if nicotinic acid deficient.
cancer reduced. reduced
antidiabetic   significant; antioxidant
AIDS – HIV infection slowed  
TOXICITY at therapeutic doses    
itch ++ . no
flushing ++ at >30mg/d if dose > 3gm/d
can cause jaundice ++ . liver protective
can cause gout yes no
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